Two‐dimensional Echocardiographic Studies during Sustained Ventricular Tachycardia

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Abstract
We evaluated left ventricular function in patients with recurrent sustained ventricular tachycardia (VT) using two‐dimensional echocardiography (2DE). Thirteen patients, 11 men and 2 women, age range 42–77 (mean 62 ± 12) years were studied in sinus rhythm (SR) and immediately after VT induction. 2DE parameters analyzed included wall motion, mitral valve leaflet motion, and ejection fraction (EF). In SR, 21 segments/walls in 12 patients showed wall motion abnormalities (WMA) ranging from hypokinesis to dyskinesis and one patient had generalized LV hypokinesis. In VT, new WMA were noted in 2 patients. Thirteen segments/walls in 8 patients showed further worsening of pre‐existing WMA. In 1 patient there was worsening of generalized LV hypokinesis. Three patients showed apparent improvement in pre‐existing WMA during VT. In 2 patients large apical aneurysms showed a reduction of dyskinesis in VT. Mitral valve opening was intermittent in patients with shorter VT cycle lengths and was maximal when atrial systole preceded or coincided with ventricular depolarization. Doppler echocardiography in 1 patient confirmed the pattern of intermittent mitral flow, with greatest flow occurring when mitral valve opening occurred well before the QRS peak. In 5 patients, 2DE permitted EF measurements. EF in SR ranged from 24–56% (mean 36 ± 13), decreased to 6–33% (mean 21 ± 11) within the first ten beats of VT and 6–25% (mean 19 ± 8) after twenty beats of VT. EF decreased more in patients with shorter VT cycles as compared to those with longer VT cycle lengths. We conclude: 1) 2DE is feasible during clinical electrophysiologic studies for sustained VT and may be a useful adjunct in studying the physiologic impact of VT; 2) WMA generally worsens during VT but can appear less evident due to declining systolic function in adjacent viable myocardium; 3) VT cycle length is a major determinant of hemodynamic compromise and atrial systole may contribute to cardiac output at slow VT rates.