TY - JOUR
T1 - Effect of electrical activation site on left ventricular performance in ventricular tachycardia patients with coronary heart disease
AU - Raichlen, Joel S.
AU - Links, Jonathan M.
AU - Reid, Philip R.
N1 - Funding Information:
From the Division of Cardiology, Department of Medicine and the Division of Nuclear Medicine, Department of Radiology, The Johns Hopkins Hospital, Baltimore, Maryland. This study was supported in part by Training Grant 2-T32-HL-07227 from the National Institutes of Health, Bethesda, Maryland. Manuscript received April 19, 1984; revised manuscript received August 22, 1984, accepted August 23, 1984.
PY - 1985/1/1
Y1 - 1985/1/1
N2 - Some patients with ventricular tachycardia (VT) remain virtually asymptomatic, whereas others have syncope despite similar VT rates. The role of ventricular activation site on left ventricular (LV) function was examined in 10 patients undergoing electrophysiologic evaluation for recurrent ventricular arrhythmias. Radionuclide ventriculograms were acquired to calculate LV volumes and aortic or LV pressure was measured during right atrial and right ventricular (RV) pacing. RV apical pacing resulted in end-diastolic volumes similar to those achieved with right atrial pacing (171 ± 27 vs 175 ± 19 ml), whereas RV outflow tract pacing showed a trend toward lower volumes (168 ± 32 vs 177 ± 33 ml). Comparison between RV apical and RV outflow tract pacing showed that apical activation resulted in higher end-diastolic volumes (216 ± 26 vs 194 ± 22 ml, p = 0.020), end-systolic volumes (175 ± 25 vs 158 ± 20 ml, p = 0.041), stroke volumes (42 ± 4 vs 36 ± 6 ml, p = 0.046), peak rates of LV ejection (309 ± 57 vs 245 ± 40 ml/s, p = 0.034) and peak rates normalized for differences in end-diastolic volume (1.5 ± 0.3 vs 1.3 ± 0.3; p = 0.047) without a significant increase in peak pressures (131 ± 12 vs 127 ± 14 mm Hg, p > 0.30) or ejection fractions (24 ± 5 vs 22 ± 4%, p = 0.187). These changes were accompanied by an increase in LV RV stroke count ratios during RV apical vs RV outflow tract pacing (1.6 ± 0.2 vs 1.2 ± 0.2, p = 0.030), suggesting the development of mitral regurgitation. Temporal Fourier analysis of the radionuclide ventriculograms showed considerable variation in the LV patterns of emptying from different activation sites. It is hypothesized that the altered activation sequence associated with RV apical pacing disrupts papillary muscle function, inducing mitral regurgitation and, as a consequence, results in higher LV volumes and ejection rates than RV outflow tract activation. These site-dependent differences in LV performance suggest that the location of ventricular activation may be an important determinant of the hemodynamic consequences of sustained ventricular tachyarrhythmias.
AB - Some patients with ventricular tachycardia (VT) remain virtually asymptomatic, whereas others have syncope despite similar VT rates. The role of ventricular activation site on left ventricular (LV) function was examined in 10 patients undergoing electrophysiologic evaluation for recurrent ventricular arrhythmias. Radionuclide ventriculograms were acquired to calculate LV volumes and aortic or LV pressure was measured during right atrial and right ventricular (RV) pacing. RV apical pacing resulted in end-diastolic volumes similar to those achieved with right atrial pacing (171 ± 27 vs 175 ± 19 ml), whereas RV outflow tract pacing showed a trend toward lower volumes (168 ± 32 vs 177 ± 33 ml). Comparison between RV apical and RV outflow tract pacing showed that apical activation resulted in higher end-diastolic volumes (216 ± 26 vs 194 ± 22 ml, p = 0.020), end-systolic volumes (175 ± 25 vs 158 ± 20 ml, p = 0.041), stroke volumes (42 ± 4 vs 36 ± 6 ml, p = 0.046), peak rates of LV ejection (309 ± 57 vs 245 ± 40 ml/s, p = 0.034) and peak rates normalized for differences in end-diastolic volume (1.5 ± 0.3 vs 1.3 ± 0.3; p = 0.047) without a significant increase in peak pressures (131 ± 12 vs 127 ± 14 mm Hg, p > 0.30) or ejection fractions (24 ± 5 vs 22 ± 4%, p = 0.187). These changes were accompanied by an increase in LV RV stroke count ratios during RV apical vs RV outflow tract pacing (1.6 ± 0.2 vs 1.2 ± 0.2, p = 0.030), suggesting the development of mitral regurgitation. Temporal Fourier analysis of the radionuclide ventriculograms showed considerable variation in the LV patterns of emptying from different activation sites. It is hypothesized that the altered activation sequence associated with RV apical pacing disrupts papillary muscle function, inducing mitral regurgitation and, as a consequence, results in higher LV volumes and ejection rates than RV outflow tract activation. These site-dependent differences in LV performance suggest that the location of ventricular activation may be an important determinant of the hemodynamic consequences of sustained ventricular tachyarrhythmias.
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U2 - 10.1016/0002-9149(85)90304-2
DO - 10.1016/0002-9149(85)90304-2
M3 - Article
C2 - 3966402
AN - SCOPUS:0021959001
SN - 0002-9149
VL - 55
SP - 84
EP - 88
JO - The American journal of cardiology
JF - The American journal of cardiology
IS - 1
ER -