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Research paper thumbnail of Results of a Minimally Invasive Surgical Pulmonary Vein Isolation and Ganglionic Plexi Ablation for Atrial Fibrillation Single-Center Experience With 12Month Follow-Up

Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its c... more Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its complexity and requirement for cardiopulmonary bypass. Long-term follow-up and success using criteria established by the Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society consensus statement have not been reported for surgical AF ablation. We describe the results of using a thorascopic approach and radiofrequency energy to perform bilateral pulmonary vein isolation and left atrial ganglionic plexi ablation for treatment of AF. Methods and Results-Forty-five (33 paroxysmal; 12 persistent) consecutive patients underwent thorascopic bilateral radiofrequency pulmonary vein isolation, ganglionic plexi ablation, ligament of Marshall ablation, and left atrial appendage exclusion by a single surgeon. Forty-three patients were prospectively followed without antiarrhythmic drugs for a minimum of 1 year with a 30-day continuous event monitor or pacemaker interrogation at 6 and 12 months. Failure was defined as any atrial tachyarrhythmia of Ͼ30 seconds' duration occurring Ͼ90 days after surgery. Mean follow-up was 516Ϯ181 days (202 to 858 days). Twenty-eight (65%) patients had no atrial tachyarrhythmia Ͼ30 seconds by 1 year, and 15 (35%) patients had atrial tachyarrhythmia recurrences by 1 year. Eight of 15 patients with recurrent AF had catheter ablation resulting in elimination and/or reduction of AF episodes in 7 of 8 patients. Four of 15 patients had AF elimination or reduction with antiarrhythmic drugs alone. Three patients did not benefit from surgery and received rate control only. There were no deaths; 1 phrenic nerve injury and 2 pleural effusions were the only major complications.

Research paper thumbnail of Implantable cardiac defibrillator lead failure or myopotential oversensing? An approach to the diagnosis of noise on lead electrograms

Europace, 2008

The appearance of noise on electrograms (EGMs) recorded from the lead of an implantable cardiover... more The appearance of noise on electrograms (EGMs) recorded from the lead of an implantable cardioverterdefibrillator (ICD) may be owing to oversensing of myopotentials, insulation breach, conductor coil fracture, loose set screw, or electromagnetic interference from an external source. The extraneous noise may lead to inappropriate shocks or inhibition of pacing. We describe two cases of pectoral myopotentials oversensing in patients with ICD and an approach to distinguish among the various extraneous noises recorded on EGMs. A systematic approach to identify the cause of the noise is important to render an appropriate treatment, which might include simple device re-programming or require reoperation and lead revision or replacement.

Research paper thumbnail of A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

European Journal of Cardio-thoracic Surgery, 2007

A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass ... more A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

Research paper thumbnail of Results of a Minimally Invasive Surgical Pulmonary Vein Isolation and Ganglionic Plexi Ablation for Atrial Fibrillation: Single-Center Experience With 12Month Follow-Up

Circulation-arrhythmia and Electrophysiology, 2009

Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its c... more Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its complexity and requirement for cardiopulmonary bypass. Long-term follow-up and success using criteria established by the Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society consensus statement have not been reported for surgical AF ablation. We describe the results of using a thorascopic approach and radiofrequency energy to perform bilateral pulmonary vein isolation and left atrial ganglionic plexi ablation for treatment of AF. Methods and Results-Forty-five (33 paroxysmal; 12 persistent) consecutive patients underwent thorascopic bilateral radiofrequency pulmonary vein isolation, ganglionic plexi ablation, ligament of Marshall ablation, and left atrial appendage exclusion by a single surgeon. Forty-three patients were prospectively followed without antiarrhythmic drugs for a minimum of 1 year with a 30-day continuous event monitor or pacemaker interrogation at 6 and 12 months. Failure was defined as any atrial tachyarrhythmia of Ͼ30 seconds' duration occurring Ͼ90 days after surgery. Mean follow-up was 516Ϯ181 days (202 to 858 days). Twenty-eight (65%) patients had no atrial tachyarrhythmia Ͼ30 seconds by 1 year, and 15 (35%) patients had atrial tachyarrhythmia recurrences by 1 year. Eight of 15 patients with recurrent AF had catheter ablation resulting in elimination and/or reduction of AF episodes in 7 of 8 patients. Four of 15 patients had AF elimination or reduction with antiarrhythmic drugs alone. Three patients did not benefit from surgery and received rate control only. There were no deaths; 1 phrenic nerve injury and 2 pleural effusions were the only major complications.

Research paper thumbnail of Prolongation of the QTc Interval Is Seen Uniformly During Early Transmural Ischemia

In order to more clearly understand the electrocardiographic manifestations of early transmural i... more In order to more clearly understand the electrocardiographic manifestations of early transmural ischemia, we studied electrocardiograms (ECGs) in patients undergoing balloon angioplasty. Decisions regarding reperfusion strategies in patients with acute myocardial infarction rely largely on the presence of ST-segment elevation (STE) in the ECG, consequently with significant limitations. Studies of the "ischemic cascade" show that ST-segment changes occur well after the onset of wall motion abnormalities. We prospectively analyzed ECGs obtained at 20-s intervals in 74 patients undergoing elective balloon angioplasty. The ECGs were analyzed using 3 methodologies. In 74 patients, the ST-segment, the T-wave, and the QT-interval were analyzed using the MUSE (General Electric HC, Menomonee Falls, Wisconsin) automated system (MUSE). Fifty patients were also analyzed using the Interval Editor automated system (IE; General Electric HC). In 20 patients, measurements were made manually. Transmural ischemia prolonged the QTc interval (using the Bazett's formula) in 100% of patients. In all 74 patients analyzed with MUSE, QTc interval prolonged from 423 +/- 25 ms to 455 +/- 34 ms (p < 0.001). In the 50 patients analyzed with IE, QTc interval prolonged in 50 of 50 (100%) patients (from 424 +/- 27 ms to 458 +/- 33 ms [p < 0.001]). Mean time to maximal QTc interval prolongation, changes in T-wave polarity, > or =1 mm STE, and ST-segment depression (STD) were 22, 24, 29, and 35 s, respectively. Although QTc interval prolonged in 100% of patients, T-wave changes, STE, and STD (> or =1 mm) occurred in 7%, 15%, and 7%, respectively. The QTc interval prolongs in 100% of patients with early transmural ischemia. When compared with clinically accepted indexes of transmural ischemia (i.e., STD and STE [> or =1 mm]) it is the earliest ECG abnormality.

Research paper thumbnail of An alternative technique of implanting a nontransvenous implantable cardioverter-defibrillator system in adults with no or limited venous access to the heart

Research paper thumbnail of Review A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

Summary Percutaneous intervention (PCI) and minimally invasive direct coronary bypass grafting (M... more Summary Percutaneous intervention (PCI) and minimally invasive direct coronary bypass grafting (MIDCAB) are both well-accepted treatment options for isolated high-grade stenosis of proximal left anterior descending coronary artery. Small studies comparing the two modalities have yielded conflicting results. We performed a meta-analysis of randomized control trials to compare percutaneous intervention with minimally invasive coronary bypass grafting for isolated proximal left anterior descending artery stenosis. Five randomized trials with a total of 711 patients and average follow-up of 2.3 years were included in the analysis; 380 patients received stents and 331 underwent surgery. Only one trial used drug eluting stents. There were a small number of events overall in each trial. Difference between mortality was 12 events versus 15 between the PCI versus MIDCABgroup. Similarly, the difference in myocardial infarction was 14versus10,and targetvesselrevascularization was56versus19. The relative risk for stentingversus MIDCAB was 0.96 ((95% CI: 0.47, 1.99),p = 0.92,I2 = 17.5%),for mortality and myocardial infarction, 0.77 ((95% CI: 0.30, 2.01), p = 0.60, I2 = 10.4%) for mortality and 1.81 ((95% CI: 0.80, 4.06), p = 0.15, I2 = 65.9%) for the composite end point of mortality, myocardial infarction and target vessel revascularization. Excluding the trial with drug eluting stents the relative risk for the composite outcome of mortality, myocardial infarction and target vessel revascularization was significantly higher for PCI (RR = 2.27 (95% CI: 1.32, 3.90), p = 0.003, I2 = 18.9%). Overall mortality and myocardial infarction rates are similar for bare metal stents versus MIDCAB, but surgery was associated with significantly lower rates of repeat revascularization. The number of randomized patients and events were small. The effect of drug eluting stents might close the gap of repeat revascularization compared to MIDCAB for this disease. # 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Research paper thumbnail of Sensing Failure Associated with the Medtronic Sprint Fidelis Defibrillator Lead

Journal of Cardiovascular Electrophysiology, 2008

Introduction: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progr... more Introduction: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progressively smaller over time. However, the long-term performance characteristics of these smaller ICD leads are unknown.Methods: We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis™ defibrillating lead at two separate centers between September 2004 and October 2006. Lead characteristics were measured at implant, at early follow-up (1–4 days post implant), and every 3–6 months thereafter.Results: During the study period, 357 patients underwent implantation of the Medtronic Sprint Fidelis™ lead. The mean R-wave measured at implant through the device was not different (P = NS) when compared with that measured at first follow-up (10.5 ± 5.0 mV vs 10.7 ± 5.1 mV). Forty-one patients (13%) had an R-wave amplitude ≤ 5 mV measured through the device at implant. Of those patients with an R-wave amplitude ≤ 5 mV at implant measured through the device, 63% (n = 26) remained ≤ 5 mV for the duration of follow-up. The mean time to R-wave amplitude ≤ 5 mV was 96.2 ± 123 days. During follow-up, 65 (18%) patients developed R-wave ≤ 5 mV. Overall 10 lead revisions (2.8%) were performed during the first year of follow-up.Conclusion: Abnormal R-wave sensing is frequently observed during follow-up with the Medtronic Fidelis ICD lead. Lead revision was necessary in 2.8% of the patients, most often (8 of 10) due to abnormal R-wave sensing along with elevated pacing threshold. Whether this issue is limited to this lead or reflects a potential problem with all downsized ICD leads merits further investigation.

Research paper thumbnail of Prolongation of the QTc Interval Is Seen Uniformly During Early Transmural Ischemia

Journal of The American College of Cardiology, 2007

In order to more clearly understand the electrocardiographic manifestations of early transmural i... more In order to more clearly understand the electrocardiographic manifestations of early transmural ischemia, we studied electrocardiograms (ECGs) in patients undergoing balloon angioplasty. Decisions regarding reperfusion strategies in patients with acute myocardial infarction rely largely on the presence of ST-segment elevation (STE) in the ECG, consequently with significant limitations. Studies of the "ischemic cascade" show that ST-segment changes occur well after the onset of wall motion abnormalities. We prospectively analyzed ECGs obtained at 20-s intervals in 74 patients undergoing elective balloon angioplasty. The ECGs were analyzed using 3 methodologies. In 74 patients, the ST-segment, the T-wave, and the QT-interval were analyzed using the MUSE (General Electric HC, Menomonee Falls, Wisconsin) automated system (MUSE). Fifty patients were also analyzed using the Interval Editor automated system (IE; General Electric HC). In 20 patients, measurements were made manually. Transmural ischemia prolonged the QTc interval (using the Bazett's formula) in 100% of patients. In all 74 patients analyzed with MUSE, QTc interval prolonged from 423 +/- 25 ms to 455 +/- 34 ms (p < 0.001). In the 50 patients analyzed with IE, QTc interval prolonged in 50 of 50 (100%) patients (from 424 +/- 27 ms to 458 +/- 33 ms [p < 0.001]). Mean time to maximal QTc interval prolongation, changes in T-wave polarity, > or =1 mm STE, and ST-segment depression (STD) were 22, 24, 29, and 35 s, respectively. Although QTc interval prolonged in 100% of patients, T-wave changes, STE, and STD (> or =1 mm) occurred in 7%, 15%, and 7%, respectively. The QTc interval prolongs in 100% of patients with early transmural ischemia. When compared with clinically accepted indexes of transmural ischemia (i.e., STD and STE [> or =1 mm]) it is the earliest ECG abnormality.

Research paper thumbnail of Results of a Minimally Invasive Surgical Pulmonary Vein Isolation and Ganglionic Plexi Ablation for Atrial Fibrillation Single-Center Experience With 12Month Follow-Up

Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its c... more Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its complexity and requirement for cardiopulmonary bypass. Long-term follow-up and success using criteria established by the Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society consensus statement have not been reported for surgical AF ablation. We describe the results of using a thorascopic approach and radiofrequency energy to perform bilateral pulmonary vein isolation and left atrial ganglionic plexi ablation for treatment of AF. Methods and Results-Forty-five (33 paroxysmal; 12 persistent) consecutive patients underwent thorascopic bilateral radiofrequency pulmonary vein isolation, ganglionic plexi ablation, ligament of Marshall ablation, and left atrial appendage exclusion by a single surgeon. Forty-three patients were prospectively followed without antiarrhythmic drugs for a minimum of 1 year with a 30-day continuous event monitor or pacemaker interrogation at 6 and 12 months. Failure was defined as any atrial tachyarrhythmia of Ͼ30 seconds' duration occurring Ͼ90 days after surgery. Mean follow-up was 516Ϯ181 days (202 to 858 days). Twenty-eight (65%) patients had no atrial tachyarrhythmia Ͼ30 seconds by 1 year, and 15 (35%) patients had atrial tachyarrhythmia recurrences by 1 year. Eight of 15 patients with recurrent AF had catheter ablation resulting in elimination and/or reduction of AF episodes in 7 of 8 patients. Four of 15 patients had AF elimination or reduction with antiarrhythmic drugs alone. Three patients did not benefit from surgery and received rate control only. There were no deaths; 1 phrenic nerve injury and 2 pleural effusions were the only major complications.

Research paper thumbnail of Implantable cardiac defibrillator lead failure or myopotential oversensing? An approach to the diagnosis of noise on lead electrograms

Europace, 2008

The appearance of noise on electrograms (EGMs) recorded from the lead of an implantable cardiover... more The appearance of noise on electrograms (EGMs) recorded from the lead of an implantable cardioverterdefibrillator (ICD) may be owing to oversensing of myopotentials, insulation breach, conductor coil fracture, loose set screw, or electromagnetic interference from an external source. The extraneous noise may lead to inappropriate shocks or inhibition of pacing. We describe two cases of pectoral myopotentials oversensing in patients with ICD and an approach to distinguish among the various extraneous noises recorded on EGMs. A systematic approach to identify the cause of the noise is important to render an appropriate treatment, which might include simple device re-programming or require reoperation and lead revision or replacement.

Research paper thumbnail of A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

European Journal of Cardio-thoracic Surgery, 2007

A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass ... more A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

Research paper thumbnail of Results of a Minimally Invasive Surgical Pulmonary Vein Isolation and Ganglionic Plexi Ablation for Atrial Fibrillation: Single-Center Experience With 12Month Follow-Up

Circulation-arrhythmia and Electrophysiology, 2009

Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its c... more Maze procedure for treatment of medically refractory atrial fibrillation (AF) is limited by its complexity and requirement for cardiopulmonary bypass. Long-term follow-up and success using criteria established by the Heart Rhythm Society/European Heart Rhythm Association/European Cardiac Arrhythmia Society consensus statement have not been reported for surgical AF ablation. We describe the results of using a thorascopic approach and radiofrequency energy to perform bilateral pulmonary vein isolation and left atrial ganglionic plexi ablation for treatment of AF. Methods and Results-Forty-five (33 paroxysmal; 12 persistent) consecutive patients underwent thorascopic bilateral radiofrequency pulmonary vein isolation, ganglionic plexi ablation, ligament of Marshall ablation, and left atrial appendage exclusion by a single surgeon. Forty-three patients were prospectively followed without antiarrhythmic drugs for a minimum of 1 year with a 30-day continuous event monitor or pacemaker interrogation at 6 and 12 months. Failure was defined as any atrial tachyarrhythmia of Ͼ30 seconds' duration occurring Ͼ90 days after surgery. Mean follow-up was 516Ϯ181 days (202 to 858 days). Twenty-eight (65%) patients had no atrial tachyarrhythmia Ͼ30 seconds by 1 year, and 15 (35%) patients had atrial tachyarrhythmia recurrences by 1 year. Eight of 15 patients with recurrent AF had catheter ablation resulting in elimination and/or reduction of AF episodes in 7 of 8 patients. Four of 15 patients had AF elimination or reduction with antiarrhythmic drugs alone. Three patients did not benefit from surgery and received rate control only. There were no deaths; 1 phrenic nerve injury and 2 pleural effusions were the only major complications.

Research paper thumbnail of Prolongation of the QTc Interval Is Seen Uniformly During Early Transmural Ischemia

In order to more clearly understand the electrocardiographic manifestations of early transmural i... more In order to more clearly understand the electrocardiographic manifestations of early transmural ischemia, we studied electrocardiograms (ECGs) in patients undergoing balloon angioplasty. Decisions regarding reperfusion strategies in patients with acute myocardial infarction rely largely on the presence of ST-segment elevation (STE) in the ECG, consequently with significant limitations. Studies of the "ischemic cascade" show that ST-segment changes occur well after the onset of wall motion abnormalities. We prospectively analyzed ECGs obtained at 20-s intervals in 74 patients undergoing elective balloon angioplasty. The ECGs were analyzed using 3 methodologies. In 74 patients, the ST-segment, the T-wave, and the QT-interval were analyzed using the MUSE (General Electric HC, Menomonee Falls, Wisconsin) automated system (MUSE). Fifty patients were also analyzed using the Interval Editor automated system (IE; General Electric HC). In 20 patients, measurements were made manually. Transmural ischemia prolonged the QTc interval (using the Bazett's formula) in 100% of patients. In all 74 patients analyzed with MUSE, QTc interval prolonged from 423 +/- 25 ms to 455 +/- 34 ms (p < 0.001). In the 50 patients analyzed with IE, QTc interval prolonged in 50 of 50 (100%) patients (from 424 +/- 27 ms to 458 +/- 33 ms [p < 0.001]). Mean time to maximal QTc interval prolongation, changes in T-wave polarity, > or =1 mm STE, and ST-segment depression (STD) were 22, 24, 29, and 35 s, respectively. Although QTc interval prolonged in 100% of patients, T-wave changes, STE, and STD (> or =1 mm) occurred in 7%, 15%, and 7%, respectively. The QTc interval prolongs in 100% of patients with early transmural ischemia. When compared with clinically accepted indexes of transmural ischemia (i.e., STD and STE [> or =1 mm]) it is the earliest ECG abnormality.

Research paper thumbnail of An alternative technique of implanting a nontransvenous implantable cardioverter-defibrillator system in adults with no or limited venous access to the heart

Research paper thumbnail of Review A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery

Summary Percutaneous intervention (PCI) and minimally invasive direct coronary bypass grafting (M... more Summary Percutaneous intervention (PCI) and minimally invasive direct coronary bypass grafting (MIDCAB) are both well-accepted treatment options for isolated high-grade stenosis of proximal left anterior descending coronary artery. Small studies comparing the two modalities have yielded conflicting results. We performed a meta-analysis of randomized control trials to compare percutaneous intervention with minimally invasive coronary bypass grafting for isolated proximal left anterior descending artery stenosis. Five randomized trials with a total of 711 patients and average follow-up of 2.3 years were included in the analysis; 380 patients received stents and 331 underwent surgery. Only one trial used drug eluting stents. There were a small number of events overall in each trial. Difference between mortality was 12 events versus 15 between the PCI versus MIDCABgroup. Similarly, the difference in myocardial infarction was 14versus10,and targetvesselrevascularization was56versus19. The relative risk for stentingversus MIDCAB was 0.96 ((95% CI: 0.47, 1.99),p = 0.92,I2 = 17.5%),for mortality and myocardial infarction, 0.77 ((95% CI: 0.30, 2.01), p = 0.60, I2 = 10.4%) for mortality and 1.81 ((95% CI: 0.80, 4.06), p = 0.15, I2 = 65.9%) for the composite end point of mortality, myocardial infarction and target vessel revascularization. Excluding the trial with drug eluting stents the relative risk for the composite outcome of mortality, myocardial infarction and target vessel revascularization was significantly higher for PCI (RR = 2.27 (95% CI: 1.32, 3.90), p = 0.003, I2 = 18.9%). Overall mortality and myocardial infarction rates are similar for bare metal stents versus MIDCAB, but surgery was associated with significantly lower rates of repeat revascularization. The number of randomized patients and events were small. The effect of drug eluting stents might close the gap of repeat revascularization compared to MIDCAB for this disease. # 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Research paper thumbnail of Sensing Failure Associated with the Medtronic Sprint Fidelis Defibrillator Lead

Journal of Cardiovascular Electrophysiology, 2008

Introduction: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progr... more Introduction: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progressively smaller over time. However, the long-term performance characteristics of these smaller ICD leads are unknown.Methods: We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis™ defibrillating lead at two separate centers between September 2004 and October 2006. Lead characteristics were measured at implant, at early follow-up (1–4 days post implant), and every 3–6 months thereafter.Results: During the study period, 357 patients underwent implantation of the Medtronic Sprint Fidelis™ lead. The mean R-wave measured at implant through the device was not different (P = NS) when compared with that measured at first follow-up (10.5 ± 5.0 mV vs 10.7 ± 5.1 mV). Forty-one patients (13%) had an R-wave amplitude ≤ 5 mV measured through the device at implant. Of those patients with an R-wave amplitude ≤ 5 mV at implant measured through the device, 63% (n = 26) remained ≤ 5 mV for the duration of follow-up. The mean time to R-wave amplitude ≤ 5 mV was 96.2 ± 123 days. During follow-up, 65 (18%) patients developed R-wave ≤ 5 mV. Overall 10 lead revisions (2.8%) were performed during the first year of follow-up.Conclusion: Abnormal R-wave sensing is frequently observed during follow-up with the Medtronic Fidelis ICD lead. Lead revision was necessary in 2.8% of the patients, most often (8 of 10) due to abnormal R-wave sensing along with elevated pacing threshold. Whether this issue is limited to this lead or reflects a potential problem with all downsized ICD leads merits further investigation.

Research paper thumbnail of Prolongation of the QTc Interval Is Seen Uniformly During Early Transmural Ischemia

Journal of The American College of Cardiology, 2007

In order to more clearly understand the electrocardiographic manifestations of early transmural i... more In order to more clearly understand the electrocardiographic manifestations of early transmural ischemia, we studied electrocardiograms (ECGs) in patients undergoing balloon angioplasty. Decisions regarding reperfusion strategies in patients with acute myocardial infarction rely largely on the presence of ST-segment elevation (STE) in the ECG, consequently with significant limitations. Studies of the "ischemic cascade" show that ST-segment changes occur well after the onset of wall motion abnormalities. We prospectively analyzed ECGs obtained at 20-s intervals in 74 patients undergoing elective balloon angioplasty. The ECGs were analyzed using 3 methodologies. In 74 patients, the ST-segment, the T-wave, and the QT-interval were analyzed using the MUSE (General Electric HC, Menomonee Falls, Wisconsin) automated system (MUSE). Fifty patients were also analyzed using the Interval Editor automated system (IE; General Electric HC). In 20 patients, measurements were made manually. Transmural ischemia prolonged the QTc interval (using the Bazett's formula) in 100% of patients. In all 74 patients analyzed with MUSE, QTc interval prolonged from 423 +/- 25 ms to 455 +/- 34 ms (p < 0.001). In the 50 patients analyzed with IE, QTc interval prolonged in 50 of 50 (100%) patients (from 424 +/- 27 ms to 458 +/- 33 ms [p < 0.001]). Mean time to maximal QTc interval prolongation, changes in T-wave polarity, > or =1 mm STE, and ST-segment depression (STD) were 22, 24, 29, and 35 s, respectively. Although QTc interval prolonged in 100% of patients, T-wave changes, STE, and STD (> or =1 mm) occurred in 7%, 15%, and 7%, respectively. The QTc interval prolongs in 100% of patients with early transmural ischemia. When compared with clinically accepted indexes of transmural ischemia (i.e., STD and STE [> or =1 mm]) it is the earliest ECG abnormality.