16 research outputs found
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Age, Gender, and Autonomic Tone Effects on Surface Electrocardiographic Indices of Ventricular Repolarization
Differences in the Rate of Implantable Cardioverter Defibrillator (ICD) Discharge between Patients Receiving ICD’s for Primary vs. Secondary Prevention of SCD
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Is All Ventricular Fibrillation the Same? Influence of Mode of Induction on Characteristics of Ventricular Fibrillation
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Acute blood pressure effects at the onset of supraventricular and ventricular tachycardia
This study was designed to assess the effects of tachycardia origin, the significance of atrial contribution, and the effects of left ventricular ejection fraction on hemodynamically tolerated ventricular tachycardia (VT) and supraventricular tachycardia (SVT). Forty-one subjects with inducible hemodynamically tolerated VT (n = 24) or SVT (n = 17) with mean ages of 60 ± 13 and 40 ± 16 years and mean ejection fractions of 32 ± 15% and 59 ± 5%, respectively, were studied. VT and SVT were induced by standard techniques, and femoral arterial blood pressure (BP) was recorded for 30 seconds. After tachycardia termination, with ≥3 minutes between conditions, ventricular overdrive pacing was performed from the right ventricular (RV) apex and then the RV outflow tract, followed by atrioventricular (AV) pacing at the tachycardia cycle length. Mean BP was measured every 5 seconds. Linear regression methods were used to model BP response for the 2 groups. There was a significant increase in BP over the 20-second interval after the induction of VT and SVT (0.55 ± 0.21 and 1.0 ± 0.20 mm Hg/s, respectively, p <0.05). In patients with hemodynamically tolerated VT, RV apex and RV outflow tract pacing at the tachycardia cycle length decreased BP by 6.7 ± 2.0 (p <0.002) and 4.7 ± 2.5 mm Hg (p = 0.06), respectively. AV pacing at the tachycardia cycle length did not improve BP compared with RV pacing alone. In patients with SVT, RV apex and RV outflow pacing at the tachycardia cycle length decreased BP by 5.6 ± 2.9 (p = 0.05) and 4.1 ± 2.7 mm Hg (p = 0.12), respectively. However, AV pacing at the tachycardia cycle length was associated with improved BP response over RV pacing alone. Increased age and lower ejection fraction adversely influenced BP response in the VT group and longer cycle length, and higher preinduction BP favorably influenced BP response in the SVT group. The determinants of BP response after tachycardia onset are complex and differ in patients with SVT and VT
Is there a correlation between ventricular fibrillation cycle length and electrophysiological and anatomic properties of the canine left ventricle?
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Excitable Gap in Canine Fibrillating Ventricular Myocardium: Effect of Subacute and Chronic Myocardial Infarction
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Effects of Sex and Age on Electrocardiographic and Cardiac Electrophysiological Properties in Adults
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Is There a Correlation between Ventricular Fibrillation Cycle Length and Electrophysiological and Anatomic Properties of the Canine Left Ventricle?
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