Zarko Calovic - Academia.edu (original) (raw)
Papers by Zarko Calovic
Srpski arhiv za celokupno lekarstvo, 2011
Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective thera... more Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective therapeutic option for rate control in atrial fibrillation (AF) and heart failure (HF). However, there is controversy regarding the long-term outcome of the procedure, since right ventricular stimulation can lead to left ventricular remodelling and HF. The aim of the study was to determine a 5-year outcome of the procedure on survival, HF control and myocardial function in patients with HF and uncontrolled AF. All patients with AF and HF who underwent AV-junction ablation with pacemaker implantation in our institution were followed after the procedure. HF diagnosis was established if > or = 2 of the following criteria were present: 1) ejection fraction (EF) < or = 45%; 2) previous episode of congestive HF (CHF); 3) NYHA-class > or = 2; and 4) use of drug-therapy for HF. Study included 32 patients (25 males; 53.4 +/- 9.6 years). The mean heart rate was 121 +/- 25 bpm before and 75 +/- 10 bpm after ablation (p=0.001). Over the follow-up of 5.0 +/- 4.0 years nine patients (28.1%) died (five died suddenly, three of terminal CHF and one of stroke). After the procedure, CHF occurrence was reduced (p=0.001), as well as the annual number of hospitalizations (p=0.001) and the number of drugs for CHF (p=0.028). In addition, NYHA-class and EF were improved, from 3.3 +/- 0.7 to 1.6 +/- 0.8 (p<0.001) and from 39 +/- 11% to 51 +/- 10% (p<0.001), respectively. In HF patients with uncontrolled AF, 5-year mortality after AV-junction ablation and pacemaker implantation was 28%. In the majority of these patients good rate of AF and HF control were achieved, as well as the improvement of functional status and myocardial contractility.
Srpski arhiv za celokupno lekarstvo, 2005
Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treati... more Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treating patients with systolic heart failure, with echocardiograph signs of ventricular asynchrony and a prolonged QRS of longer than 120 milliseconds. This method has been accepted in most medical centres around the world and was instigated in our Pacemaker Centre in December 2001, 3 months after FDA approval for human use. The aim of the study was to present this new procedure and the results obtained from our own group of patients. A multi-site, biventricular pacemaker, with a special electrode for left-half heart stimulation was implanted in the coronary sinus of 17 patients who had suffered systolic heart failure (12 male and 5 female, average age 59.9 years). For all of them, the duration of the QRS interval was longer than 120 ms, with left bundle branch morphology, and an ejection fraction below 30%. All the patients were NYHA class II or III. Prior to and after the implantation, a 12-channel ECG and ECHO were carried out, a 6-minute hall walk test was performed, additionally, the total walked distance on a flat surface was measured, the general condition of the patient was evaluated, the number of medications being taken was noted, as was the number of days of hospitalisation. The average time from diagnosis to implantation was 22 months, and the average post-operative follow-up was 14 months. Two of the patients died 10 and 7 months after the implantation, due to a new myocardial infarction and refractory heart failure. In addition, one patient did not show any improvement after the implantation of the multi-site pacemaker (there were three "non-responder" patients). All the other patients felt much better: decreased NYHA class for I - II class, increased left ventricle ejection fraction, reduced use of diuretics, increased 6-minute hall walk distance and general walk distance on a flat surface, and decreased number of days of hospitalisation. Resynchronisation heart failure therapy in the majority of patients with systolic left ventricular dysfunction and a prolonged QRS interval considerably improves cardiac function, in addition to reducing symptoms and hospital stays.
Pacing and Clinical Electrophysiology, 2008
The aim of the study was to analyze endovenous pacing lead survival in pediatric population impla... more The aim of the study was to analyze endovenous pacing lead survival in pediatric population implanted by cephalic cut down, or by axillary vein puncture.
Journal of the American College of Cardiology, 2004
Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients... more Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients with severe, drug-refractory heart failure. The clinical results are promising, and improvement in symptoms, exercise capacity, and systolic left ventricular (LV) function have been demonstrated after CRT, accompanied by a reduction in hospitalization and a superior survival as compared with optimized medical therapy alone. However, 20% to 30% of patients do not respond to CRT. Currently, patients are selected mainly on electrocardiogram criteria (wide QRS complex, left bundle branch block configuration). In view of the 20% to 30% of nonresponders, additional selection criteria are needed. Echocardiography (and, in particular, tissue Doppler imaging) may allow further identification of potential responders to CRT, based on assessment of inter-and intraventricular dyssynchrony. In addition, echocardiography may allow optimal LV lead positioning and follow-up after CRT. In the current review, the different echocardiographic approaches to predict response to CRT are discussed. In addition, the use of echocardiography to guide LV lead positioning and follow-up after CRT are addressed. (J Am Coll Cardiol 2004;44:1-9)
Circulation, Jan 19, 2015
We thank Fenici et al for their interest in our experience on the natural history of the Wolff-Pa... more We thank Fenici et al for their interest in our experience on the natural history of the Wolff-Parkinson-White (WPW) syndrome. The authors, on the basis of their experience, suggest the routine use of ambulatory transesophageal atrial pacing (TEAP) as an intermediate approach to minimize "invasiveness" for risk assessment in the asymptomatic WPW population. It is well known that, unlike invasive electrophysiological testing (EPT), TEAP provides less accurate information about "the real electrophysiological profile of the risk" in WPW patients. Potential limitations are an approximate value of the anterograde refractory period of accessory pathways (APs), no identification of multiple APs, no reproducibility or inducibility of atrial fibrillation, no information on AP retrograde conduction, and no AP localization, all of which in a modern electrophysiology laboratory are indeed unacceptable when evaluating the risk of sudden death. Currently, in the era of widespread use of radiofrequency catheter ablation (RFA), more accurate information on the electrophysiological characteristics of potentially dangerous AP is indeed required to definitively eliminate the risk of sudden death. 1-5 Recently, we have seen an 11-year-old asymptomatic boy who, after discovering incidentally before a practice the presence of ventricular pre-excitation on the ECG, was reassured after a "negative" ambulatory TEAP (no inducibility of any arrhythmia). Unfortunately, 3 years later, this "good asymptomatic boy" underwent both EPT and RFA of AP immediately after experiencing a resuscitated cardiac arrest caused by ventricular fibrillation as demonstrated by EPT. Because asymptomatic ventricular preexcitation has been supposed for many decades to be at no or minimal risk of sudden death, it is comprehensible that in the pre-RFA era this ambulatory strategy began to be used to stratify a "benign" disease. Besides these important methodological and physiopathological considerations, TEAP is a semi-invasive technique and is not entirely risk free. High-output pacing may frequently be required to activate the atrium from the esophagus, which can be painful, requiring the use of heavy sedation, all of which can modify the electrophysiological properties of AP. Albeit rarely, TEAP may also induce ventricular tachyarrhythmias, including ventricular fibrillation. Our experience with >11 000 WPW patients indicates that in a modern electrophysiology laboratory EPT and RFA performed in the same session are both safe and effective to definitively eliminate the risk of sudden death in patients with ventricular pre-excitation regardless of symptoms. We believe that TEAP remains a pioneering approach in the pre-RFA era that nowadays has become anachronistic, being abandoned by most modern electrophysiology laboratories worldwide, as shown by the fact that in the last 30 years the use of TEAP in patients with WPW syndrome has not been reported in the literature. Our large experience indicates that the risk of sudden death in patients with ventricular pre-excitation essentially depends on intrinsic electrophysiological AP properties rather than on symptoms. Thus, EPT indeed represents the gold standard to more accurately characterize in the single patient the electrophysiological properties of potentially dangerous AP to correctly identify subjects at risk of sudden death for prophylactic ablation.
Srpski arhiv za celokupno lekarstvo, 2011
Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective thera... more Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective therapeutic option for rate control in atrial fibrillation (AF) and heart failure (HF). However, there is controversy regarding the long-term outcome of the procedure, since right ventricular stimulation can lead to left ventricular remodelling and HF. The aim of the study was to determine a 5-year outcome of the procedure on survival, HF control and myocardial function in patients with HF and uncontrolled AF. All patients with AF and HF who underwent AV-junction ablation with pacemaker implantation in our institution were followed after the procedure. HF diagnosis was established if > or = 2 of the following criteria were present: 1) ejection fraction (EF) < or = 45%; 2) previous episode of congestive HF (CHF); 3) NYHA-class > or = 2; and 4) use of drug-therapy for HF. Study included 32 patients (25 males; 53.4 +/- 9.6 years). The mean heart rate was 121 +/- 25 bpm before and 75 +/- 10 bpm after ablation (p=0.001). Over the follow-up of 5.0 +/- 4.0 years nine patients (28.1%) died (five died suddenly, three of terminal CHF and one of stroke). After the procedure, CHF occurrence was reduced (p=0.001), as well as the annual number of hospitalizations (p=0.001) and the number of drugs for CHF (p=0.028). In addition, NYHA-class and EF were improved, from 3.3 +/- 0.7 to 1.6 +/- 0.8 (p<0.001) and from 39 +/- 11% to 51 +/- 10% (p<0.001), respectively. In HF patients with uncontrolled AF, 5-year mortality after AV-junction ablation and pacemaker implantation was 28%. In the majority of these patients good rate of AF and HF control were achieved, as well as the improvement of functional status and myocardial contractility.
Srpski arhiv za celokupno lekarstvo
Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treati... more Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treating patients with systolic heart failure, with echocardiograph signs of ventricular asynchrony and a prolonged QRS of longer than 120 milliseconds. This method has been accepted in most medical centres around the world and was instigated in our Pacemaker Centre in December 2001, 3 months after FDA approval for human use. The aim of the study was to present this new procedure and the results obtained from our own group of patients. A multi-site, biventricular pacemaker, with a special electrode for left-half heart stimulation was implanted in the coronary sinus of 17 patients who had suffered systolic heart failure (12 male and 5 female, average age 59.9 years). For all of them, the duration of the QRS interval was longer than 120 ms, with left bundle branch morphology, and an ejection fraction below 30%. All the patients were NYHA class II or III. Prior to and after the implantation, a 12...
Pacing and Clinical Electrophysiology, 2008
The aim of the study was to analyze endovenous pacing lead survival in pediatric population impla... more The aim of the study was to analyze endovenous pacing lead survival in pediatric population implanted by cephalic cut down, or by axillary vein puncture.
Journal of the American College of Cardiology, 2004
Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients... more Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients with severe, drug-refractory heart failure. The clinical results are promising, and improvement in symptoms, exercise capacity, and systolic left ventricular (LV) function have been demonstrated after CRT, accompanied by a reduction in hospitalization and a superior survival as compared with optimized medical therapy alone. However, 20% to 30% of patients do not respond to CRT. Currently, patients are selected mainly on electrocardiogram criteria (wide QRS complex, left bundle branch block configuration). In view of the 20% to 30% of nonresponders, additional selection criteria are needed. Echocardiography (and, in particular, tissue Doppler imaging) may allow further identification of potential responders to CRT, based on assessment of inter-and intraventricular dyssynchrony. In addition, echocardiography may allow optimal LV lead positioning and follow-up after CRT. In the current review, the different echocardiographic approaches to predict response to CRT are discussed. In addition, the use of echocardiography to guide LV lead positioning and follow-up after CRT are addressed. (J Am Coll Cardiol 2004;44:1-9)
Journal of the American College of Cardiology, 2011
The cost-effectiveness study was conducted from the third party payer's perspective (Italian Nati... more The cost-effectiveness study was conducted from the third party payer's perspective (Italian National Health Service, INHS), to compare RFA and ADT in patients with PAF. We collected and compared 1-year follow-up data from the 198 patients of the APAF study (JACC 2006) randomly assigned to catheter ablation (99 patients) or to new ADT (99 patients). Efficacy and direct medical costs were quantified. Sensitivity analyses were conducted to account for the uncertainties as well as to identify how estimates could vary under different assumptions for cardiovascular events (CV). Costs paid by the hospital to perform RFA were quantified and compared with the reimbursement provided by NHS. At the time of analyses (2009) 1 euro (€) corresponded to around 1.41 US (Dollars) $.
Heart Rhythm, 2014
Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. To inve... more Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. To investigate if CRT with multipoint left ventricular (LV) pacing in a single coronary sinus branch (MultiPoint Pacing [MPP], St Jude Medical, Sylmar, CA) can offer further hemodynamic benefits to patients. Forty-four consecutive patients (80% men, New York Heart Association III, end-systolic volume 180 ± 77 mL, ejection fraction 27% ± 6%, and QRS duration 152 ± 17 ms) receiving a CRT device implant (Unify Quadra MP or Quadra Assura MP and Quartet LV lead, St Jude Medical) underwent intraoperative assessment of LV hemodynamics by using a pressure-volume loop system (Inca, CD Leycom). A pacing protocol was performed, including 9 biventricular pacing interventions with conventional CRT (CONV) using distal and proximal LV electrodes and various MPP configurations. Each pacing intervention was performed twice in randomized order with right ventricular pacing (BASELINE) repeated after every intervention. Evaluable recordings were obtained in 42 patients. Relative to BASELINE, the best MPP intervention significantly increased the rate of pressure change (dP/dtmax; 15.9% ± 10.0% vs 13.5% ± 8.8%; P < .001), stroke work (27.2% ± 42.5% vs 19.4% ± 32.2%; P = .018), stroke volume (10.4% ± 22.5% vs 4.1% ± 13.1%; P = .003), and ejection fraction (10.5% ± 20.9% vs 5.3% ± 13.2%; P = .003) as compared with the best CONV intervention. Moreover, the best MPP intervention improved acute diastolic function, significantly decreasing -dP/dtmin (-13.5% ± 10.2% vs -10.6% ± 6.8%; P = .011), relaxation time constant (-7.5% ± 9.0% vs -4.8% ± 7.2%; P = .012), and end-diastolic pressure (-18.2% ± 22.4% vs -8.7% ± 21.4%; P < .001) as compared with the best CONV intervention. CRT with MPP can significantly improve acute LV hemodynamic parameters assessed with pressure-volume loop measurements as compared with CONV.
Echocardiography, 2012
Objectives: The aim of this study was to assess the performance of echocardiographic parameters t... more Objectives: The aim of this study was to assess the performance of echocardiographic parameters to predict response to cardiac resynchronization therapy (CRT). Background: CRT reduces morbidity and mortality due to the proper selection of candidates for CRT. Methods: The 12-month trial was performed on 70 optimally medicated patients with standard inclusion criteria: NYHA class III or IV heart failure, left ventricular ejection fraction (LVEF) ≤ 35%, and QRS ≥ 120 ms. All parameters were evaluated by conventional and tissue Doppler-based methods. Indicator of positive CRT response was more than 20% in improvement of LVEF. Results: LVEF increased >20% in 42 patients. Out of 43 tested baseline echocardiographic parameters, 12 showed statistical difference between responders and nonresponders. Out of these 12 parameters, six (LVSV, LVSI, LVFS, RVd, VPMR, and PISA) had modest to moderately good ability to predict LVEF response with sensitivity ranging from 62.2% to 82.4%, and specificity ranging from 56.5% to 81.2%. For those parameters, the area under the receiver-operating characteristic curve for positive response to CRT was ≤0.76. Multivariate regression analysis resulted in selection of LVSI and LVFS as possible predictive independent parameters for a good response. The cutoff value for LVSI was 38.7 mL/m 2 (P = 0.045) and for LVFS was 13% (P = 0.032). Conclusions: Contribution of LVSI and LVFS is to be confirmed in larger trials. Simplicity of their assessment by conventional echocardiography could be an argument for adding them to the inclusion criteria for CRT in severe heart failure patients. (Echocardiography 2012;29:267-275) Cardiac resynchronization therapy (CRT) is a validated therapy for patients with dilated cardiomyopathy (DCM) and severely impaired left ventricular (LV) systolic function, despite optimal medical therapy for heart failure. The standard indications, according to the ACC/AHA/ESC guidelines, for CRT are the patients with DCM, left bundle brunch block (LBBB), NYHA class III or IV, left ventricular ejection fraction (LVEF) ≤ 35%, and wide QRS complex ≥ 120 ms. 1,2 Numerous clinical studies have shown that CRT reduces morbidity and mortality, improves heart failure symptoms, quality of life, exercise capacity, and cardiac function and structure. 3-8
Srpski arhiv za celokupno lekarstvo, 2005
ABSTRACT The implantable loop recorder (ILR) is a new diagnostic tool in cardiology for establish... more ABSTRACT The implantable loop recorder (ILR) is a new diagnostic tool in cardiology for establishing the causes of unexplained syncope in patients where standard conventional tests, invasive tests included, have failed. The device is a diagnostic "pacemaker," surgically implanted underneath the skin of the chest, with leads attached to the case of the device, not requiring endovenous lead implantation. Heart rhythm is monitored continuously on the basis of an endless loop, up to a maximum period of 14 months. Recording is carried out either by applying an outside activator whenever symptoms occur, or automatically, according to a pre-set algorithm for bradycardia, tachycardia, and/or asystolic detection. The aim of this study was to present this new diagnostic method as well as our first experiences with its implementation. We followed 5 patients (3 male, 2 female, mean age: 46.4 +/- 19) who had ILRs ("Reveal Plus," Medtronic Inc., USA) implanted at our centre, over a period of 14 months (7.6 +/- 5.5), concentrating on their clinical course, symptom occurrence, and electronically monitored heart rhythm at the time of ILR auto activation and/or recordings triggered by outside activation whenever a patient's symptoms were discernible. In three patients, the ILR revealed syncope aetiology by documenting heart rhythm at the time of its occurrence. In one patient, involving a lethal outcome, the ILR was not explanted, so that the rhythm at the time of the fatal syncope, although assumed, remained undocumented. In one, most recently implanted patient, follow-up is still in progress. The implantable loop recorder represents an important innovation and a step forward in establishing the causes of recurrent syncope, which cannot be determined by standard invasive and non-invasive testing.
Srpski arhiv za celokupno lekarstvo, 2011
Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective thera... more Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective therapeutic option for rate control in atrial fibrillation (AF) and heart failure (HF). However, there is controversy regarding the long-term outcome of the procedure, since right ventricular stimulation can lead to left ventricular remodelling and HF. The aim of the study was to determine a 5-year outcome of the procedure on survival, HF control and myocardial function in patients with HF and uncontrolled AF. All patients with AF and HF who underwent AV-junction ablation with pacemaker implantation in our institution were followed after the procedure. HF diagnosis was established if > or = 2 of the following criteria were present: 1) ejection fraction (EF) < or = 45%; 2) previous episode of congestive HF (CHF); 3) NYHA-class > or = 2; and 4) use of drug-therapy for HF. Study included 32 patients (25 males; 53.4 +/- 9.6 years). The mean heart rate was 121 +/- 25 bpm before and 75 +/- 10 bpm after ablation (p=0.001). Over the follow-up of 5.0 +/- 4.0 years nine patients (28.1%) died (five died suddenly, three of terminal CHF and one of stroke). After the procedure, CHF occurrence was reduced (p=0.001), as well as the annual number of hospitalizations (p=0.001) and the number of drugs for CHF (p=0.028). In addition, NYHA-class and EF were improved, from 3.3 +/- 0.7 to 1.6 +/- 0.8 (p<0.001) and from 39 +/- 11% to 51 +/- 10% (p<0.001), respectively. In HF patients with uncontrolled AF, 5-year mortality after AV-junction ablation and pacemaker implantation was 28%. In the majority of these patients good rate of AF and HF control were achieved, as well as the improvement of functional status and myocardial contractility.
Srpski arhiv za celokupno lekarstvo, 2005
Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treati... more Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treating patients with systolic heart failure, with echocardiograph signs of ventricular asynchrony and a prolonged QRS of longer than 120 milliseconds. This method has been accepted in most medical centres around the world and was instigated in our Pacemaker Centre in December 2001, 3 months after FDA approval for human use. The aim of the study was to present this new procedure and the results obtained from our own group of patients. A multi-site, biventricular pacemaker, with a special electrode for left-half heart stimulation was implanted in the coronary sinus of 17 patients who had suffered systolic heart failure (12 male and 5 female, average age 59.9 years). For all of them, the duration of the QRS interval was longer than 120 ms, with left bundle branch morphology, and an ejection fraction below 30%. All the patients were NYHA class II or III. Prior to and after the implantation, a 12-channel ECG and ECHO were carried out, a 6-minute hall walk test was performed, additionally, the total walked distance on a flat surface was measured, the general condition of the patient was evaluated, the number of medications being taken was noted, as was the number of days of hospitalisation. The average time from diagnosis to implantation was 22 months, and the average post-operative follow-up was 14 months. Two of the patients died 10 and 7 months after the implantation, due to a new myocardial infarction and refractory heart failure. In addition, one patient did not show any improvement after the implantation of the multi-site pacemaker (there were three "non-responder" patients). All the other patients felt much better: decreased NYHA class for I - II class, increased left ventricle ejection fraction, reduced use of diuretics, increased 6-minute hall walk distance and general walk distance on a flat surface, and decreased number of days of hospitalisation. Resynchronisation heart failure therapy in the majority of patients with systolic left ventricular dysfunction and a prolonged QRS interval considerably improves cardiac function, in addition to reducing symptoms and hospital stays.
Pacing and Clinical Electrophysiology, 2008
The aim of the study was to analyze endovenous pacing lead survival in pediatric population impla... more The aim of the study was to analyze endovenous pacing lead survival in pediatric population implanted by cephalic cut down, or by axillary vein puncture.
Journal of the American College of Cardiology, 2004
Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients... more Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients with severe, drug-refractory heart failure. The clinical results are promising, and improvement in symptoms, exercise capacity, and systolic left ventricular (LV) function have been demonstrated after CRT, accompanied by a reduction in hospitalization and a superior survival as compared with optimized medical therapy alone. However, 20% to 30% of patients do not respond to CRT. Currently, patients are selected mainly on electrocardiogram criteria (wide QRS complex, left bundle branch block configuration). In view of the 20% to 30% of nonresponders, additional selection criteria are needed. Echocardiography (and, in particular, tissue Doppler imaging) may allow further identification of potential responders to CRT, based on assessment of inter-and intraventricular dyssynchrony. In addition, echocardiography may allow optimal LV lead positioning and follow-up after CRT. In the current review, the different echocardiographic approaches to predict response to CRT are discussed. In addition, the use of echocardiography to guide LV lead positioning and follow-up after CRT are addressed. (J Am Coll Cardiol 2004;44:1-9)
Circulation, Jan 19, 2015
We thank Fenici et al for their interest in our experience on the natural history of the Wolff-Pa... more We thank Fenici et al for their interest in our experience on the natural history of the Wolff-Parkinson-White (WPW) syndrome. The authors, on the basis of their experience, suggest the routine use of ambulatory transesophageal atrial pacing (TEAP) as an intermediate approach to minimize "invasiveness" for risk assessment in the asymptomatic WPW population. It is well known that, unlike invasive electrophysiological testing (EPT), TEAP provides less accurate information about "the real electrophysiological profile of the risk" in WPW patients. Potential limitations are an approximate value of the anterograde refractory period of accessory pathways (APs), no identification of multiple APs, no reproducibility or inducibility of atrial fibrillation, no information on AP retrograde conduction, and no AP localization, all of which in a modern electrophysiology laboratory are indeed unacceptable when evaluating the risk of sudden death. Currently, in the era of widespread use of radiofrequency catheter ablation (RFA), more accurate information on the electrophysiological characteristics of potentially dangerous AP is indeed required to definitively eliminate the risk of sudden death. 1-5 Recently, we have seen an 11-year-old asymptomatic boy who, after discovering incidentally before a practice the presence of ventricular pre-excitation on the ECG, was reassured after a "negative" ambulatory TEAP (no inducibility of any arrhythmia). Unfortunately, 3 years later, this "good asymptomatic boy" underwent both EPT and RFA of AP immediately after experiencing a resuscitated cardiac arrest caused by ventricular fibrillation as demonstrated by EPT. Because asymptomatic ventricular preexcitation has been supposed for many decades to be at no or minimal risk of sudden death, it is comprehensible that in the pre-RFA era this ambulatory strategy began to be used to stratify a "benign" disease. Besides these important methodological and physiopathological considerations, TEAP is a semi-invasive technique and is not entirely risk free. High-output pacing may frequently be required to activate the atrium from the esophagus, which can be painful, requiring the use of heavy sedation, all of which can modify the electrophysiological properties of AP. Albeit rarely, TEAP may also induce ventricular tachyarrhythmias, including ventricular fibrillation. Our experience with >11 000 WPW patients indicates that in a modern electrophysiology laboratory EPT and RFA performed in the same session are both safe and effective to definitively eliminate the risk of sudden death in patients with ventricular pre-excitation regardless of symptoms. We believe that TEAP remains a pioneering approach in the pre-RFA era that nowadays has become anachronistic, being abandoned by most modern electrophysiology laboratories worldwide, as shown by the fact that in the last 30 years the use of TEAP in patients with WPW syndrome has not been reported in the literature. Our large experience indicates that the risk of sudden death in patients with ventricular pre-excitation essentially depends on intrinsic electrophysiological AP properties rather than on symptoms. Thus, EPT indeed represents the gold standard to more accurately characterize in the single patient the electrophysiological properties of potentially dangerous AP to correctly identify subjects at risk of sudden death for prophylactic ablation.
Srpski arhiv za celokupno lekarstvo, 2011
Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective thera... more Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective therapeutic option for rate control in atrial fibrillation (AF) and heart failure (HF). However, there is controversy regarding the long-term outcome of the procedure, since right ventricular stimulation can lead to left ventricular remodelling and HF. The aim of the study was to determine a 5-year outcome of the procedure on survival, HF control and myocardial function in patients with HF and uncontrolled AF. All patients with AF and HF who underwent AV-junction ablation with pacemaker implantation in our institution were followed after the procedure. HF diagnosis was established if > or = 2 of the following criteria were present: 1) ejection fraction (EF) < or = 45%; 2) previous episode of congestive HF (CHF); 3) NYHA-class > or = 2; and 4) use of drug-therapy for HF. Study included 32 patients (25 males; 53.4 +/- 9.6 years). The mean heart rate was 121 +/- 25 bpm before and 75 +/- 10 bpm after ablation (p=0.001). Over the follow-up of 5.0 +/- 4.0 years nine patients (28.1%) died (five died suddenly, three of terminal CHF and one of stroke). After the procedure, CHF occurrence was reduced (p=0.001), as well as the annual number of hospitalizations (p=0.001) and the number of drugs for CHF (p=0.028). In addition, NYHA-class and EF were improved, from 3.3 +/- 0.7 to 1.6 +/- 0.8 (p<0.001) and from 39 +/- 11% to 51 +/- 10% (p<0.001), respectively. In HF patients with uncontrolled AF, 5-year mortality after AV-junction ablation and pacemaker implantation was 28%. In the majority of these patients good rate of AF and HF control were achieved, as well as the improvement of functional status and myocardial contractility.
Srpski arhiv za celokupno lekarstvo
Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treati... more Resynchronisation therapy with biventricular permanent pacing stimulation is one method of treating patients with systolic heart failure, with echocardiograph signs of ventricular asynchrony and a prolonged QRS of longer than 120 milliseconds. This method has been accepted in most medical centres around the world and was instigated in our Pacemaker Centre in December 2001, 3 months after FDA approval for human use. The aim of the study was to present this new procedure and the results obtained from our own group of patients. A multi-site, biventricular pacemaker, with a special electrode for left-half heart stimulation was implanted in the coronary sinus of 17 patients who had suffered systolic heart failure (12 male and 5 female, average age 59.9 years). For all of them, the duration of the QRS interval was longer than 120 ms, with left bundle branch morphology, and an ejection fraction below 30%. All the patients were NYHA class II or III. Prior to and after the implantation, a 12...
Pacing and Clinical Electrophysiology, 2008
The aim of the study was to analyze endovenous pacing lead survival in pediatric population impla... more The aim of the study was to analyze endovenous pacing lead survival in pediatric population implanted by cephalic cut down, or by axillary vein puncture.
Journal of the American College of Cardiology, 2004
Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients... more Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients with severe, drug-refractory heart failure. The clinical results are promising, and improvement in symptoms, exercise capacity, and systolic left ventricular (LV) function have been demonstrated after CRT, accompanied by a reduction in hospitalization and a superior survival as compared with optimized medical therapy alone. However, 20% to 30% of patients do not respond to CRT. Currently, patients are selected mainly on electrocardiogram criteria (wide QRS complex, left bundle branch block configuration). In view of the 20% to 30% of nonresponders, additional selection criteria are needed. Echocardiography (and, in particular, tissue Doppler imaging) may allow further identification of potential responders to CRT, based on assessment of inter-and intraventricular dyssynchrony. In addition, echocardiography may allow optimal LV lead positioning and follow-up after CRT. In the current review, the different echocardiographic approaches to predict response to CRT are discussed. In addition, the use of echocardiography to guide LV lead positioning and follow-up after CRT are addressed. (J Am Coll Cardiol 2004;44:1-9)
Journal of the American College of Cardiology, 2011
The cost-effectiveness study was conducted from the third party payer's perspective (Italian Nati... more The cost-effectiveness study was conducted from the third party payer's perspective (Italian National Health Service, INHS), to compare RFA and ADT in patients with PAF. We collected and compared 1-year follow-up data from the 198 patients of the APAF study (JACC 2006) randomly assigned to catheter ablation (99 patients) or to new ADT (99 patients). Efficacy and direct medical costs were quantified. Sensitivity analyses were conducted to account for the uncertainties as well as to identify how estimates could vary under different assumptions for cardiovascular events (CV). Costs paid by the hospital to perform RFA were quantified and compared with the reimbursement provided by NHS. At the time of analyses (2009) 1 euro (€) corresponded to around 1.41 US (Dollars) $.
Heart Rhythm, 2014
Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. To inve... more Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. To investigate if CRT with multipoint left ventricular (LV) pacing in a single coronary sinus branch (MultiPoint Pacing [MPP], St Jude Medical, Sylmar, CA) can offer further hemodynamic benefits to patients. Forty-four consecutive patients (80% men, New York Heart Association III, end-systolic volume 180 ± 77 mL, ejection fraction 27% ± 6%, and QRS duration 152 ± 17 ms) receiving a CRT device implant (Unify Quadra MP or Quadra Assura MP and Quartet LV lead, St Jude Medical) underwent intraoperative assessment of LV hemodynamics by using a pressure-volume loop system (Inca, CD Leycom). A pacing protocol was performed, including 9 biventricular pacing interventions with conventional CRT (CONV) using distal and proximal LV electrodes and various MPP configurations. Each pacing intervention was performed twice in randomized order with right ventricular pacing (BASELINE) repeated after every intervention. Evaluable recordings were obtained in 42 patients. Relative to BASELINE, the best MPP intervention significantly increased the rate of pressure change (dP/dtmax; 15.9% ± 10.0% vs 13.5% ± 8.8%; P < .001), stroke work (27.2% ± 42.5% vs 19.4% ± 32.2%; P = .018), stroke volume (10.4% ± 22.5% vs 4.1% ± 13.1%; P = .003), and ejection fraction (10.5% ± 20.9% vs 5.3% ± 13.2%; P = .003) as compared with the best CONV intervention. Moreover, the best MPP intervention improved acute diastolic function, significantly decreasing -dP/dtmin (-13.5% ± 10.2% vs -10.6% ± 6.8%; P = .011), relaxation time constant (-7.5% ± 9.0% vs -4.8% ± 7.2%; P = .012), and end-diastolic pressure (-18.2% ± 22.4% vs -8.7% ± 21.4%; P < .001) as compared with the best CONV intervention. CRT with MPP can significantly improve acute LV hemodynamic parameters assessed with pressure-volume loop measurements as compared with CONV.
Echocardiography, 2012
Objectives: The aim of this study was to assess the performance of echocardiographic parameters t... more Objectives: The aim of this study was to assess the performance of echocardiographic parameters to predict response to cardiac resynchronization therapy (CRT). Background: CRT reduces morbidity and mortality due to the proper selection of candidates for CRT. Methods: The 12-month trial was performed on 70 optimally medicated patients with standard inclusion criteria: NYHA class III or IV heart failure, left ventricular ejection fraction (LVEF) ≤ 35%, and QRS ≥ 120 ms. All parameters were evaluated by conventional and tissue Doppler-based methods. Indicator of positive CRT response was more than 20% in improvement of LVEF. Results: LVEF increased >20% in 42 patients. Out of 43 tested baseline echocardiographic parameters, 12 showed statistical difference between responders and nonresponders. Out of these 12 parameters, six (LVSV, LVSI, LVFS, RVd, VPMR, and PISA) had modest to moderately good ability to predict LVEF response with sensitivity ranging from 62.2% to 82.4%, and specificity ranging from 56.5% to 81.2%. For those parameters, the area under the receiver-operating characteristic curve for positive response to CRT was ≤0.76. Multivariate regression analysis resulted in selection of LVSI and LVFS as possible predictive independent parameters for a good response. The cutoff value for LVSI was 38.7 mL/m 2 (P = 0.045) and for LVFS was 13% (P = 0.032). Conclusions: Contribution of LVSI and LVFS is to be confirmed in larger trials. Simplicity of their assessment by conventional echocardiography could be an argument for adding them to the inclusion criteria for CRT in severe heart failure patients. (Echocardiography 2012;29:267-275) Cardiac resynchronization therapy (CRT) is a validated therapy for patients with dilated cardiomyopathy (DCM) and severely impaired left ventricular (LV) systolic function, despite optimal medical therapy for heart failure. The standard indications, according to the ACC/AHA/ESC guidelines, for CRT are the patients with DCM, left bundle brunch block (LBBB), NYHA class III or IV, left ventricular ejection fraction (LVEF) ≤ 35%, and wide QRS complex ≥ 120 ms. 1,2 Numerous clinical studies have shown that CRT reduces morbidity and mortality, improves heart failure symptoms, quality of life, exercise capacity, and cardiac function and structure. 3-8
Srpski arhiv za celokupno lekarstvo, 2005
ABSTRACT The implantable loop recorder (ILR) is a new diagnostic tool in cardiology for establish... more ABSTRACT The implantable loop recorder (ILR) is a new diagnostic tool in cardiology for establishing the causes of unexplained syncope in patients where standard conventional tests, invasive tests included, have failed. The device is a diagnostic "pacemaker," surgically implanted underneath the skin of the chest, with leads attached to the case of the device, not requiring endovenous lead implantation. Heart rhythm is monitored continuously on the basis of an endless loop, up to a maximum period of 14 months. Recording is carried out either by applying an outside activator whenever symptoms occur, or automatically, according to a pre-set algorithm for bradycardia, tachycardia, and/or asystolic detection. The aim of this study was to present this new diagnostic method as well as our first experiences with its implementation. We followed 5 patients (3 male, 2 female, mean age: 46.4 +/- 19) who had ILRs ("Reveal Plus," Medtronic Inc., USA) implanted at our centre, over a period of 14 months (7.6 +/- 5.5), concentrating on their clinical course, symptom occurrence, and electronically monitored heart rhythm at the time of ILR auto activation and/or recordings triggered by outside activation whenever a patient's symptoms were discernible. In three patients, the ILR revealed syncope aetiology by documenting heart rhythm at the time of its occurrence. In one patient, involving a lethal outcome, the ILR was not explanted, so that the rhythm at the time of the fatal syncope, although assumed, remained undocumented. In one, most recently implanted patient, follow-up is still in progress. The implantable loop recorder represents an important innovation and a step forward in establishing the causes of recurrent syncope, which cannot be determined by standard invasive and non-invasive testing.