Barry Bertolet - Academia.edu (original) (raw)
Papers by Barry Bertolet
Clinical Cardiology, 1999
Buckground: The epicardial electrocardiogram (ECG) is a sensitive marker for cardiac ischemia and... more Buckground: The epicardial electrocardiogram (ECG) is a sensitive marker for cardiac ischemia and has been used as a measure of ischemia in clinical trials. We sought to examine the utility of a central ECG laboratory for determining ischemic-type ST-segment shifts from epicardial ECG recordings obtained from multiple clinical sites.
Catheterization and Cardiovascular Diagnosis, 1996
It is not known how the site of arterial administration of heparin and the timing of the activate... more It is not known how the site of arterial administration of heparin and the timing of the activated clotting time (ACT) measurement affect the ACT during coronary interventions. We measured serial femoral venous ACTs after heparin was administered either via the angioplasty guiding catheter into the central aorta or peripherally via a sheath into the femoral artery. When heparin was administered into the central aorta, the ACT rose gradually and by 60 sec plateaued without further increase. When heparin was given into the femoral artery, the ACT displayed a marked "overshoot" early (20-270 sec after heparin) and did not plateau until sometime between 270 and 800 sec after heparin administration. We conclude that the site of administration and timing of venous sampling markedly affect the measured ACT during coronary interventions. Operators should be aware of these effects when assessing the accuracy of the ACT during coronary interventions.
J Amer Coll Cardiol, 1998
and non.oxldalNo glycotysts incremental areas (AAUCs, 0-30 mln end 3060 min) were measured during... more and non.oxldalNo glycotysts incremental areas (AAUCs, 0-30 mln end 3060 min) were measured during this period, Results; Basel ET-1 levels were Ngher in sub)eels with Sx then in C (8,23 = 065 w 3,90 f 1.16 pg/ml; p • 0007) while basal NO, insulin and glucose levels were similar In both groups. Alter Insulin bolus, the AAUCs of ET-1 wore similar while the AAUCs of NO were significantly lower In subjects with Sx than in C (p < 0.01), The AAUCs of forearm glucose uptake (FGU) and glucose oxidation wore significantly decreased by 40% and by 110% In sub)eels with $x compared to C, No differences were found measuring the AAUCs of non oxidative glycolysls and of glucose storage, A negative correlation was found I~clweon the AAUCe (30,60 rain of Er.1 and of glucose oxldat¢on, and belweon tl~e AAUCs (30=60 rain) of NO and of non.oxidative glycolysls, Cortclus/oas: An tmbslan0e between ET-1 end NO release Is a feature of Sx disease and seems to Influence to some extent muscle oxidative and non.oxidative gtycolysls,
Journal of behavioral medicine, 2003
This study examined the contribution of biomedical and psychological variables in the report of a... more This study examined the contribution of biomedical and psychological variables in the report of anginal frequency at 6-week, 6- and 12-month follow-up in patients who received angioplasty with and without stent. Patients (N = 70) completed a battery of standardized questionnaries, including measures of depression, anxiety, and anger. Principal components analysis computed a single factor of negative emotion for use as a predictor in regression analyses. For the 6-week model, only baseline anginal frequency predicted anginal frequency. Negative emotion joined baseline anginal frequency in the prediction model for 6-month anginal frequency, and collectively accounted for 23% of the variance. For the 12-month model, baseline anginal frequency, female sex, and negative emotions remained in the model, accounting for 46% of the variance in anginal frequency. These results highlight the importance of biomedical and psychosocial variables in predicting anginal frequency with psychological v...
Catheterization and cardiovascular diagnosis, 1996
It is not known how the site of arterial administration of heparin and the timing of the activate... more It is not known how the site of arterial administration of heparin and the timing of the activated clotting time (ACT) measurement affect the ACT during coronary interventions. We measured serial femoral venous ACTs after heparin was administered either via the angioplasty guiding catheter into the central aorta or peripherally via a sheath into the femoral artery. When heparin was administered into the central aorta, the ACT rose gradually and by 60 sec plateaued without further increase. When heparin was given into the femoral artery, the ACT displayed a marked "overshoot" early (20-270 sec after heparin) and did not plateau until sometime between 270 and 800 sec after heparin administration. We conclude that the site of administration and timing of venous sampling markedly affect the measured ACT during coronary interventions. Operators should be aware of these effects when assessing the accuracy of the ACT during coronary interventions.
Progress in Cardiovascular Diseases, 1992
Recent investigations of SMI occurring during daily life have advanced our understanding of the p... more Recent investigations of SMI occurring during daily life have advanced our understanding of the pathophysiology of myocardial ischemia. These contributions have directed our attention away from "chest pain" alone and physical exertion as the central provoking factor toward transient myocardial ischemia and its broader triggers and consequences. Transient myocardial ischemic episodes, the majority of which are silent, are found in a subset of patients with any clinical manifestations of CAD (eg, stable angina, unstable angina, myocardial infarction, and sudden death), as well as in those patients with CAD who are and have been totally asymptomatic. These episodes are an independent predictor of increased risk for future cardiac events. Most medical therapy and revascularization therapies have the potential to prevent or relieve these silent episodes; however, we do not yet know which method is superior in reducing SMI episodes or preventing future cardiac events. Furthermore, the benefit of reducing SMI versus the cost and potential morbidity of these chosen therapies is not known. At least three trials are now underway to examine some of these concerns (Table 2). Focus on pain relief alone does not appear to be an adequate approach to alter outcome in patients with CAD and may prove insufficient to control SMI. Until these issues are resolved, we believe a conservative approach to the management of patients with CAD is warranted. Documentation of ischemia (painful or painless) is essential. Three general principles should be kept in mind. First, the presence of detectable ischemia is of central importance. This information should be used in the overall risk assessment of the patient. Second, the level of concern or aggressiveness of treatment should be based on the risk associated with the ischemic abnormalities documented (Table 3). The exercise stress test is the most useful to begin this process. The detection of ischemic-type ST-segment depression, either silent or painful, at a low workload (eg, less than or equal to 120 beats per minute or less than or equal to 6.5 metabolic equivalents [METS]) implies high risk for adverse outcome. Likewise, these ST-segment changes occurring in leads that reflect multiple coronary artery distribution, of greater than 2 mm in magnitude and persisting for greater than 6 minutes, are all markers for high risk. Thallium redistribution defects occurring at low work loads, in multiple areas, associated with increased lung uptake and enlargement of the cardiac pool all imply high risk.(ABSTRACT TRUNCATED AT 400 WORDS)
... Prevalence of Pseudoischemic ST-Segment Changes During Ambulatory Electrocardiographic Monito... more ... Prevalence of Pseudoischemic ST-Segment Changes During Ambulatory Electrocardiographic Monitoring Barry D. Bertolet, MD, Alice F. Boyette, Cynthia A. Hofmann ... 5. Mulcahy D, Keegan J, Cunningham D, Quyyumi A, Crean P, Park A, Wright C, Fox K. Orcadian variation of ...
Catheterization and Cardiovascular Diagnosis, 1996
The presence of angiographic evidence of thrombus is generally thought to be a contraindication t... more The presence of angiographic evidence of thrombus is generally thought to be a contraindication to coronary stent placement. This report describes four patients in whom angiographic thrombus was lysed using the Dispatch infusion catheter prior to coronary stenting. Urokinase was infused via the Dispatch catheter with resolution of angiographic evidence of thrombus in all cases. No complications were encountered using this technique, and all patients had excellent angiographic results after stenting. We conclude that lysis of intracoronary thrombus using the Dispatch infusion catheter is feasible and appears safe in this small study. Further trials are needed to determine if this technique reduces the acute stent thrombosis rate compared to other techniques for stent deployment in the presence of angiographic evidence of thrombus.
Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 9, 2015
Background: The TAXUS Element (ION) platinum chromium paclitaxel-eluting stent (PtCr-PES) incorpo... more Background: The TAXUS Element (ION) platinum chromium paclitaxel-eluting stent (PtCr-PES) incorporates a thin (81μm) strut design with a similar polymer and drug dose density as prior PES. The pivotal PERSEUS trial program consisted of two studies: PERSEUS Workhorse (WH) and PERSEUS Small Vessel (SV). The PERSEUS WH trial demonstrated the PtCr-PES to be non-inferior to the predicate TAXUS Express PES (TE-PES) for target lesion failure (TLF) at 1 year and in-segment angiographic percent diameter stenosis at 9 months. The PERSEUS SV trial demonstrated the PtCr-PES to be superior to a historical bare metal stent (BMS) for angiographic late lumen loss at 9 months. Long-term (5 year) clinical outcomes following PtCr-PES have not been previously reported. Methods: PERSEUS WH was a prospective, Bayesian, 3:1 randomized (PtCr-PES vs. TE-PES) trial in patients with lesion length ≤28mm and vessel diameter ≥2.75 to ≤4.0mm PERSEUS SV was a prospective, single-arm trial in patients with lesion l...
Heart, 1997
Exogenous administration of adenosine induces atrial fibrillation in up to 7.0% of patients. Anim... more Exogenous administration of adenosine induces atrial fibrillation in up to 7.0% of patients. Animal studies affirm endogenous adenosine released in response to tissue hypoxia may play a mechanistic role in arrhythmias associated with myocardial ischaemia or hypoxia. Therefore, atrial fibrillation occurring early after the acute phase of myocardial infarction involving atrial tissue may be secondary to an excessive accumulation of adenosine that leads to a shortening of atrial refractory period. Early in the course of acute inferior myocardial infarction, two patients (males aged 45 and 68) suffered new onset sustained atrial fibrillation that was abrupt in onset and complicated their clinical management. They were administered 250 mg theophylline as a slow intravenous injection at a rate of 100 mg/min or until conversion to normal sinus rhythm occurred. Both patients converted to normal sinus rhythm within five minutes of the administration of theophylline. In up to 52 hours of continuous ECG monitoring after the theophylline administration the atrial fibrillation did not recur. Neither patient experienced any adverse outcome from theophylline administration. These observations are the first reported in humans or laboratory animals to suggest that atrial fibrillation, presumably due to elevated interstitial atrial concentration of adenosine caused by myocardial ischaemia, can be terminated with an adenosine receptor antagonist. However, the hypothesis that excessive accumulation of endogenous adenosine in atrial tissue may induce atrial fibrillation is well substantiated by other investigators. Thus, A1 adenosine receptor antagonists may prove to be valuable in the management of ischaemia related atrial fibrillation.
Psychosomatic Medicine, 1998
This study evaluated physiological, neuroendocrine, and psychological status and functioning of p... more This study evaluated physiological, neuroendocrine, and psychological status and functioning of patients with coronary artery disease in order to clarify their role in the expression of symptoms during myocardial ischemia (MI), and to establish repeatability of responses to mental stress. Design and methods of the study are presented. One hundred ninety-six coronary artery disease patients were examined during physical and mental stress tests in four hospitals. Eligibility criteria included narrowing of at least 50% in the diameter of at least one major coronary artery or verified history of myocardial infarction, and evidence of ischemia on an exercise treadmill test. Psychological, biochemical, and autonomic function data were obtained before, during, and after exposure to mental and exercise stressors during 2 or 3 half-days of testing. Ventricular function was assessed by radionuclide ventriculography, and daily ischemia by ambulatory electrocardiography. Sixty patients returned for a short-term mental stress repeatability study. Twenty-nine individuals presumed to be free of coronary disease were also examined to establish reference values for cardiac responses to mental stress. Study participants were 41 to 80 years of age; 83 (42%) had a history of MI, 6 (3%) of congestive heart failure, and 163 (83%) of chest pain; 170 (87%) were men; and 90 (46%) had ischemia accompanied by angina during exercise treadmill testing. Ischemia during ambulatory monitoring was found in 35 of 90 (39%) patients with and 48 of 106 (45%) patients without angina during exercise-provoked ischemia. Intraobserver variability of ejection fraction changes during bicycle exercise and two mental stress tests (Speech and Stroop) was good (kappa = 1.0, .90, and .76, respectively; percent agreement = 100, 97.5, and 93.8%, respectively). Variability of assessed wall motion abnormalities during bicycle exercise was better (kappa, agreement = 85%) than during Speech or Stroop kappa and .57, percent agreement = 70% and 82.5%, respectively). Study design, quality control data, and baseline characteristics of patients enrolled for a clinical study of symptomatic and asymptomatic myocardial ischemia are described. Lower repeatability of reading wall motion abnormalities during mental stress than during exercise may be due to smaller effects on wall motion and lack of an indicator for peak mental stress.
Journal of the American College of Cardiology, 1995
Journal of the American College of Cardiology, 1995
The survival advantage for thrombolytic treated infarct patients who exhibit prompt (90') full co... more The survival advantage for thrombolytic treated infarct patients who exhibit prompt (90') full coronary patency, grade 3, (versus incomplete, 2, or absent flow, 0,1) is well established at time points of one week or one month. The GUSTO angiographic study now allows inspection of subsequent changes, if any, in the flow grade specific patency-mortality relationships to one full year's follow up. Of 1173 patients in whom infarct artery (IRA) patency grade was established angiographically 90' after treatment was begun, 12 month follow up is available in 99.9% (1172). Patency-1 year mortality relationships were: t:~1=:~'1 ,~_ Yo 6 _~.
Journal of the American College of Cardiology, 1995
Journal of the American College of Cardiology, 2010
The aim of this study was to evaluate the safety and efficacy of the novel platinum chromium TAXU... more The aim of this study was to evaluate the safety and efficacy of the novel platinum chromium TAXUS Element paclitaxel-eluting stent (PES) compared with the TAXUS Express PES (Boston Scientific, Natick, Massachusetts) in treating coronary artery stenoses.
Journal of the American College of Cardiology, 1999
Journal of the American College of Cardiology, 1996
Objectives. We attempted to demonstrate that theophylline, an adenosine receptor antagonist, can ... more Objectives. We attempted to demonstrate that theophylline, an adenosine receptor antagonist, can reverse bradyarrhythmias after orthotopic heart transplantation.
Clinical Cardiology, 1995
Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic... more Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic therapies. These tests, however, are prone to multiple sources of bias. This investigation sought to determine the influence of varying precordial electrocardiographic (ECG) electrode placement on the detection of exercise-induced ST-segment shifts. Fifteen coronary artery disease patients with abnormal exercise tests were studied. Based on the previous exercise test, the precordial electrode position exhibiting the greatest ST-segment shift was selected ;IS the reference electrode. Four additional electrodes were placed around this reference electrode and exercise testing was performed. ECG strips were recorded every minute. The time-to-onset and -offset of ischemic-type ST-segment depression was recorded. ST-segment depression was recorded during exercise from the reference electrode in 12 of 15 patients. Ischemic-type ST-depression was also recorded in each of these 12 patients with the surrounding electrodes; however, the timeto-onset detected by all four surrounding electrodes concurred in only 9 of 12 (42%) patients. The time-to-offset of the ST-seg-men1 depression concurred in 9 of 12 (7.5%) patients. Serial ECGs recorded from similar but not exactly the same precordial ECG electrode position should yield similar results for the deteclion of ischemia, but time-to-onset or -offset of ischemia may differ by 60 s or more. Small changes in the time-to-onset and -of!Set of ischemia should not be considered reliable indicators ol' anti-ischemia efficacy.
Clinical Cardiology, 1999
Buckground: The epicardial electrocardiogram (ECG) is a sensitive marker for cardiac ischemia and... more Buckground: The epicardial electrocardiogram (ECG) is a sensitive marker for cardiac ischemia and has been used as a measure of ischemia in clinical trials. We sought to examine the utility of a central ECG laboratory for determining ischemic-type ST-segment shifts from epicardial ECG recordings obtained from multiple clinical sites.
Catheterization and Cardiovascular Diagnosis, 1996
It is not known how the site of arterial administration of heparin and the timing of the activate... more It is not known how the site of arterial administration of heparin and the timing of the activated clotting time (ACT) measurement affect the ACT during coronary interventions. We measured serial femoral venous ACTs after heparin was administered either via the angioplasty guiding catheter into the central aorta or peripherally via a sheath into the femoral artery. When heparin was administered into the central aorta, the ACT rose gradually and by 60 sec plateaued without further increase. When heparin was given into the femoral artery, the ACT displayed a marked "overshoot" early (20-270 sec after heparin) and did not plateau until sometime between 270 and 800 sec after heparin administration. We conclude that the site of administration and timing of venous sampling markedly affect the measured ACT during coronary interventions. Operators should be aware of these effects when assessing the accuracy of the ACT during coronary interventions.
J Amer Coll Cardiol, 1998
and non.oxldalNo glycotysts incremental areas (AAUCs, 0-30 mln end 3060 min) were measured during... more and non.oxldalNo glycotysts incremental areas (AAUCs, 0-30 mln end 3060 min) were measured during this period, Results; Basel ET-1 levels were Ngher in sub)eels with Sx then in C (8,23 = 065 w 3,90 f 1.16 pg/ml; p • 0007) while basal NO, insulin and glucose levels were similar In both groups. Alter Insulin bolus, the AAUCs of ET-1 wore similar while the AAUCs of NO were significantly lower In subjects with Sx than in C (p < 0.01), The AAUCs of forearm glucose uptake (FGU) and glucose oxidation wore significantly decreased by 40% and by 110% In sub)eels with $x compared to C, No differences were found measuring the AAUCs of non oxidative glycolysls and of glucose storage, A negative correlation was found I~clweon the AAUCe (30,60 rain of Er.1 and of glucose oxldat¢on, and belweon tl~e AAUCs (30=60 rain) of NO and of non.oxidative glycolysls, Cortclus/oas: An tmbslan0e between ET-1 end NO release Is a feature of Sx disease and seems to Influence to some extent muscle oxidative and non.oxidative gtycolysls,
Journal of behavioral medicine, 2003
This study examined the contribution of biomedical and psychological variables in the report of a... more This study examined the contribution of biomedical and psychological variables in the report of anginal frequency at 6-week, 6- and 12-month follow-up in patients who received angioplasty with and without stent. Patients (N = 70) completed a battery of standardized questionnaries, including measures of depression, anxiety, and anger. Principal components analysis computed a single factor of negative emotion for use as a predictor in regression analyses. For the 6-week model, only baseline anginal frequency predicted anginal frequency. Negative emotion joined baseline anginal frequency in the prediction model for 6-month anginal frequency, and collectively accounted for 23% of the variance. For the 12-month model, baseline anginal frequency, female sex, and negative emotions remained in the model, accounting for 46% of the variance in anginal frequency. These results highlight the importance of biomedical and psychosocial variables in predicting anginal frequency with psychological v...
Catheterization and cardiovascular diagnosis, 1996
It is not known how the site of arterial administration of heparin and the timing of the activate... more It is not known how the site of arterial administration of heparin and the timing of the activated clotting time (ACT) measurement affect the ACT during coronary interventions. We measured serial femoral venous ACTs after heparin was administered either via the angioplasty guiding catheter into the central aorta or peripherally via a sheath into the femoral artery. When heparin was administered into the central aorta, the ACT rose gradually and by 60 sec plateaued without further increase. When heparin was given into the femoral artery, the ACT displayed a marked "overshoot" early (20-270 sec after heparin) and did not plateau until sometime between 270 and 800 sec after heparin administration. We conclude that the site of administration and timing of venous sampling markedly affect the measured ACT during coronary interventions. Operators should be aware of these effects when assessing the accuracy of the ACT during coronary interventions.
Progress in Cardiovascular Diseases, 1992
Recent investigations of SMI occurring during daily life have advanced our understanding of the p... more Recent investigations of SMI occurring during daily life have advanced our understanding of the pathophysiology of myocardial ischemia. These contributions have directed our attention away from "chest pain" alone and physical exertion as the central provoking factor toward transient myocardial ischemia and its broader triggers and consequences. Transient myocardial ischemic episodes, the majority of which are silent, are found in a subset of patients with any clinical manifestations of CAD (eg, stable angina, unstable angina, myocardial infarction, and sudden death), as well as in those patients with CAD who are and have been totally asymptomatic. These episodes are an independent predictor of increased risk for future cardiac events. Most medical therapy and revascularization therapies have the potential to prevent or relieve these silent episodes; however, we do not yet know which method is superior in reducing SMI episodes or preventing future cardiac events. Furthermore, the benefit of reducing SMI versus the cost and potential morbidity of these chosen therapies is not known. At least three trials are now underway to examine some of these concerns (Table 2). Focus on pain relief alone does not appear to be an adequate approach to alter outcome in patients with CAD and may prove insufficient to control SMI. Until these issues are resolved, we believe a conservative approach to the management of patients with CAD is warranted. Documentation of ischemia (painful or painless) is essential. Three general principles should be kept in mind. First, the presence of detectable ischemia is of central importance. This information should be used in the overall risk assessment of the patient. Second, the level of concern or aggressiveness of treatment should be based on the risk associated with the ischemic abnormalities documented (Table 3). The exercise stress test is the most useful to begin this process. The detection of ischemic-type ST-segment depression, either silent or painful, at a low workload (eg, less than or equal to 120 beats per minute or less than or equal to 6.5 metabolic equivalents [METS]) implies high risk for adverse outcome. Likewise, these ST-segment changes occurring in leads that reflect multiple coronary artery distribution, of greater than 2 mm in magnitude and persisting for greater than 6 minutes, are all markers for high risk. Thallium redistribution defects occurring at low work loads, in multiple areas, associated with increased lung uptake and enlargement of the cardiac pool all imply high risk.(ABSTRACT TRUNCATED AT 400 WORDS)
... Prevalence of Pseudoischemic ST-Segment Changes During Ambulatory Electrocardiographic Monito... more ... Prevalence of Pseudoischemic ST-Segment Changes During Ambulatory Electrocardiographic Monitoring Barry D. Bertolet, MD, Alice F. Boyette, Cynthia A. Hofmann ... 5. Mulcahy D, Keegan J, Cunningham D, Quyyumi A, Crean P, Park A, Wright C, Fox K. Orcadian variation of ...
Catheterization and Cardiovascular Diagnosis, 1996
The presence of angiographic evidence of thrombus is generally thought to be a contraindication t... more The presence of angiographic evidence of thrombus is generally thought to be a contraindication to coronary stent placement. This report describes four patients in whom angiographic thrombus was lysed using the Dispatch infusion catheter prior to coronary stenting. Urokinase was infused via the Dispatch catheter with resolution of angiographic evidence of thrombus in all cases. No complications were encountered using this technique, and all patients had excellent angiographic results after stenting. We conclude that lysis of intracoronary thrombus using the Dispatch infusion catheter is feasible and appears safe in this small study. Further trials are needed to determine if this technique reduces the acute stent thrombosis rate compared to other techniques for stent deployment in the presence of angiographic evidence of thrombus.
Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions, Jan 9, 2015
Background: The TAXUS Element (ION) platinum chromium paclitaxel-eluting stent (PtCr-PES) incorpo... more Background: The TAXUS Element (ION) platinum chromium paclitaxel-eluting stent (PtCr-PES) incorporates a thin (81μm) strut design with a similar polymer and drug dose density as prior PES. The pivotal PERSEUS trial program consisted of two studies: PERSEUS Workhorse (WH) and PERSEUS Small Vessel (SV). The PERSEUS WH trial demonstrated the PtCr-PES to be non-inferior to the predicate TAXUS Express PES (TE-PES) for target lesion failure (TLF) at 1 year and in-segment angiographic percent diameter stenosis at 9 months. The PERSEUS SV trial demonstrated the PtCr-PES to be superior to a historical bare metal stent (BMS) for angiographic late lumen loss at 9 months. Long-term (5 year) clinical outcomes following PtCr-PES have not been previously reported. Methods: PERSEUS WH was a prospective, Bayesian, 3:1 randomized (PtCr-PES vs. TE-PES) trial in patients with lesion length ≤28mm and vessel diameter ≥2.75 to ≤4.0mm PERSEUS SV was a prospective, single-arm trial in patients with lesion l...
Heart, 1997
Exogenous administration of adenosine induces atrial fibrillation in up to 7.0% of patients. Anim... more Exogenous administration of adenosine induces atrial fibrillation in up to 7.0% of patients. Animal studies affirm endogenous adenosine released in response to tissue hypoxia may play a mechanistic role in arrhythmias associated with myocardial ischaemia or hypoxia. Therefore, atrial fibrillation occurring early after the acute phase of myocardial infarction involving atrial tissue may be secondary to an excessive accumulation of adenosine that leads to a shortening of atrial refractory period. Early in the course of acute inferior myocardial infarction, two patients (males aged 45 and 68) suffered new onset sustained atrial fibrillation that was abrupt in onset and complicated their clinical management. They were administered 250 mg theophylline as a slow intravenous injection at a rate of 100 mg/min or until conversion to normal sinus rhythm occurred. Both patients converted to normal sinus rhythm within five minutes of the administration of theophylline. In up to 52 hours of continuous ECG monitoring after the theophylline administration the atrial fibrillation did not recur. Neither patient experienced any adverse outcome from theophylline administration. These observations are the first reported in humans or laboratory animals to suggest that atrial fibrillation, presumably due to elevated interstitial atrial concentration of adenosine caused by myocardial ischaemia, can be terminated with an adenosine receptor antagonist. However, the hypothesis that excessive accumulation of endogenous adenosine in atrial tissue may induce atrial fibrillation is well substantiated by other investigators. Thus, A1 adenosine receptor antagonists may prove to be valuable in the management of ischaemia related atrial fibrillation.
Psychosomatic Medicine, 1998
This study evaluated physiological, neuroendocrine, and psychological status and functioning of p... more This study evaluated physiological, neuroendocrine, and psychological status and functioning of patients with coronary artery disease in order to clarify their role in the expression of symptoms during myocardial ischemia (MI), and to establish repeatability of responses to mental stress. Design and methods of the study are presented. One hundred ninety-six coronary artery disease patients were examined during physical and mental stress tests in four hospitals. Eligibility criteria included narrowing of at least 50% in the diameter of at least one major coronary artery or verified history of myocardial infarction, and evidence of ischemia on an exercise treadmill test. Psychological, biochemical, and autonomic function data were obtained before, during, and after exposure to mental and exercise stressors during 2 or 3 half-days of testing. Ventricular function was assessed by radionuclide ventriculography, and daily ischemia by ambulatory electrocardiography. Sixty patients returned for a short-term mental stress repeatability study. Twenty-nine individuals presumed to be free of coronary disease were also examined to establish reference values for cardiac responses to mental stress. Study participants were 41 to 80 years of age; 83 (42%) had a history of MI, 6 (3%) of congestive heart failure, and 163 (83%) of chest pain; 170 (87%) were men; and 90 (46%) had ischemia accompanied by angina during exercise treadmill testing. Ischemia during ambulatory monitoring was found in 35 of 90 (39%) patients with and 48 of 106 (45%) patients without angina during exercise-provoked ischemia. Intraobserver variability of ejection fraction changes during bicycle exercise and two mental stress tests (Speech and Stroop) was good (kappa = 1.0, .90, and .76, respectively; percent agreement = 100, 97.5, and 93.8%, respectively). Variability of assessed wall motion abnormalities during bicycle exercise was better (kappa, agreement = 85%) than during Speech or Stroop kappa and .57, percent agreement = 70% and 82.5%, respectively). Study design, quality control data, and baseline characteristics of patients enrolled for a clinical study of symptomatic and asymptomatic myocardial ischemia are described. Lower repeatability of reading wall motion abnormalities during mental stress than during exercise may be due to smaller effects on wall motion and lack of an indicator for peak mental stress.
Journal of the American College of Cardiology, 1995
Journal of the American College of Cardiology, 1995
The survival advantage for thrombolytic treated infarct patients who exhibit prompt (90') full co... more The survival advantage for thrombolytic treated infarct patients who exhibit prompt (90') full coronary patency, grade 3, (versus incomplete, 2, or absent flow, 0,1) is well established at time points of one week or one month. The GUSTO angiographic study now allows inspection of subsequent changes, if any, in the flow grade specific patency-mortality relationships to one full year's follow up. Of 1173 patients in whom infarct artery (IRA) patency grade was established angiographically 90' after treatment was begun, 12 month follow up is available in 99.9% (1172). Patency-1 year mortality relationships were: t:~1=:~'1 ,~_ Yo 6 _~.
Journal of the American College of Cardiology, 1995
Journal of the American College of Cardiology, 2010
The aim of this study was to evaluate the safety and efficacy of the novel platinum chromium TAXU... more The aim of this study was to evaluate the safety and efficacy of the novel platinum chromium TAXUS Element paclitaxel-eluting stent (PES) compared with the TAXUS Express PES (Boston Scientific, Natick, Massachusetts) in treating coronary artery stenoses.
Journal of the American College of Cardiology, 1999
Journal of the American College of Cardiology, 1996
Objectives. We attempted to demonstrate that theophylline, an adenosine receptor antagonist, can ... more Objectives. We attempted to demonstrate that theophylline, an adenosine receptor antagonist, can reverse bradyarrhythmias after orthotopic heart transplantation.
Clinical Cardiology, 1995
Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic... more Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic therapies. These tests, however, are prone to multiple sources of bias. This investigation sought to determine the influence of varying precordial electrocardiographic (ECG) electrode placement on the detection of exercise-induced ST-segment shifts. Fifteen coronary artery disease patients with abnormal exercise tests were studied. Based on the previous exercise test, the precordial electrode position exhibiting the greatest ST-segment shift was selected ;IS the reference electrode. Four additional electrodes were placed around this reference electrode and exercise testing was performed. ECG strips were recorded every minute. The time-to-onset and -offset of ischemic-type ST-segment depression was recorded. ST-segment depression was recorded during exercise from the reference electrode in 12 of 15 patients. Ischemic-type ST-depression was also recorded in each of these 12 patients with the surrounding electrodes; however, the timeto-onset detected by all four surrounding electrodes concurred in only 9 of 12 (42%) patients. The time-to-offset of the ST-seg-men1 depression concurred in 9 of 12 (7.5%) patients. Serial ECGs recorded from similar but not exactly the same precordial ECG electrode position should yield similar results for the deteclion of ischemia, but time-to-onset or -offset of ischemia may differ by 60 s or more. Small changes in the time-to-onset and -of!Set of ischemia should not be considered reliable indicators ol' anti-ischemia efficacy.