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Determinants of the hemodynamic consequence to sustained ventricular arrhythmias after a single myocardial infarction
P T Sager1, R A Perlmutter, L E Rosenfeld
1Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn.
Insights
Patients experiencing ventricular arrhythmias after a single heart attack may have cardiac arrest or stable ventricular tachycardia. Left ventricular aneurysms were more common in patients without cardiac arrest, suggesting a key difference in post-myocardial infarction arrhythmia presentation.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Ventricular arrhythmias post-myocardial infarction (MI) can lead to cardiac arrest (CA) or stable ventricular tachycardia (No CA).
- Previous studies suggest differing electrophysiologic profiles based on MI history.
- No studies have specifically examined determinants of hemodynamic consequences after a single MI.
Purpose of the Study:
- To assess factors influencing hemodynamic consequences of sustained ventricular arrhythmias more than 3 days after a single MI.
- To compare patients with CA versus those with stable ventricular tachycardia after a single MI.
Main Methods:
- Examined 82 patients resuscitated from CA (n=40) or with hemodynamically stable sustained ventricular tachycardia (n=42).
- Assessed global left ventricular ejection fraction, infarction location, time from MI to arrhythmia, coronary artery disease severity, and presence of congestive heart failure or bundle branch block.
- Performed electrophysiologic studies in 67 patients.
Main Results:
- Both groups had similar ejection fractions, infarction locations, time from MI to arrhythmia, coronary artery disease severity, and rates of heart failure or bundle branch block.
- Patients presenting without CA more frequently had left ventricular aneurysms (58% vs 28%, p=0.005).
- Sustained ventricular tachycardia was inducible in similar proportions of patients in both groups (79% vs 85%, p=NS).
Conclusions:
- Left ventricular aneurysms are a significant distinguishing feature in patients with sustained ventricular arrhythmias without cardiac arrest after a single MI.
- This finding may help elucidate the determinants of hemodynamic consequences in this patient population.
Abstract:
Patients who have sustained ventricular arrhythmias after myocardial infarction present with either a cardiac arrest or with hemodynamically stable sustained ventricular tachycardia. Recent reports have suggested a different electrophysiologic milieu in these two patient groups and a higher incidence of cardiac arrest in patients with a history of more than one myocardial infarction. No studies have examined patients with only a single previous myocardial infarction. To assess the determinants of the hemodynamic consequence of sustained ventricular arrhythmias more than 3 days after a single myocardial infarction, 82 patients who were resuscitated from arrhythmic cardiac arrest (CA group, 40 patients) or who had hemodynamically stable sustained ventricular tachycardia (No CA group, 42 patients) were examined. Patients in both groups had similar global left ventricular ejection fractions (mean +/- SD; 30% +/- 12% vs 27% +/- 12%; p = NS), proportion of patients with anterior wall infarctions as compared with the proportion of patients with inferior wall infarctions (55% vs 50%; p = NS), time from infarction to arrhythmia development, severity of coronary artery disease, and the proportion of patients with congestive heart failure or bundle branch block. Patients who presented without cardiac arrest, however, more frequently had left ventricular aneurysms (58% vs 28%; p = 0.005). Sixty-seven patients underwent baseline drug-free electrophysiologic studies. Sustained ventricular tachycardia was induced in 79% of patients in the CA group and 85% of patients in the No CA group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)