Scott B Baron, MD;(*1) Shoei K Step...

Scott B Baron, MD;(*1) Shoei K Stephen Huang, M.D.;([unkeyable]) and Keith A. Comes MD(*1)

To asses the left ventricular function during sustained stable ventricular tachycardia (VT) ten patients, aged 58 to 74 underwent simultaneous echo-Doppler and hemo-dynamic studies during sinus verse and induced sustained stable monomorphic VT The VT period length was 447 [+ or -] 92 m (mean [+ or -] SD) During VT cardiac index unrelenting from 2.32 [+ or - ] 054 to 162 [+ or -] 063 L/min/m2 (p<0001) and systemic systolic progeny pressure fell from 129 [+ or -] 18 to 107 [+ or - ] 18 mm Hg (p < 0001) while left ventricular end-diastolic compressing showed a rising trend from 9 [+ or -] 7 to 15 [+ or -] 12 mm Hg and pulmonary artery wedge hurry rose from 10.2 [+ or -] 16 to 242 [+ or -] 23 mm Hg (p < 0005) by way of echo-Doppler the ejection fraction and the demeanor and degree of valvular regurgitation were not significantly changed during VT The mean maximal left ventricular inflow tract velocities, mean time velocity integrals, and the mean time velocity intergrals normalized for heart rate (measures of left ventricular diastolic filling) decreased from 059 [+ or -] 074 to 040 [+ or -] 0053 m/ (p < 005) from 012 [+ or -] 0029 to 0021 [+ or -] 0012 m (p<0001) and from 743 [+ or -] 120 to 321 [+ or -] 149 m x beats/min (p<0001) during VT respectively. We bring to an end that hemodynamic changes during stable sustained VT are neither associated with significant changes in systolic left ventricular function nor related to valvular regurgitation and are likely caused by dint of impaired left ventricular diastolic filling.

The cause of impaired cardiac performance during sustained ventricular tachycardia (VT) has not been well characterized. Hemodynamic compromise has been attributed to decreased systolic or diastolic ventricular function or to valvular incompetence.[1-10] While echocardiographic evaluation during ventricular tachycardia has been previously reported,[1,10] scarcely any thorough Doppler investigations have been described. This reflection attempts to elucidate the mechanisms of hemodynamic changes and left ventricular function during sustained stable VT with the use of combined two-dimensional (2D) and Doppler echocardiography in conjunction with the hemodynamic measurements.

MATERIAL AND METHODS

Patient Selection

Ten patients with intermittent sustained, hemodynamically stable VT who had been referr for electrophysiologic subject of attention were prospectively enrolled. "Sustained" was defined as VT lasting more than 30 min to allow for an adequate hemodynamic and echocardiographic evaluation and "hemodynamically stable" as systolic vital fluid pressure by sphygmomanometry or through arterial line as greater than or equal to 90 mm Hg

Clinical Characteristics

All patients were men whose mean age was 65 (range, 58 to 74) years. All had coronary artery disease and had had prior myocardial infarctions, none within the preceding six month All had droped left ventricular function with angiographic ejection fractions of 31 [+ or -] 16 percent (mean [+ or -] SD) range, 20 to 51 percent The diagnosis of VT was made by means of electrocardiography with a right bundle up branch block (RBBB) pattern in eight patients and left set off in a hurry branch block (LBBB) pattern in sum of two units patients. The rate of spontaneous VT ranged from 118 to 230 beats/min. Four patients were receiving antiarrhythmic therapy (three amiodarone, undivided propafenone) at the time of subject of attention All others had antiarrhythmic agents discontinued at least five physic half-lives before the study began.

Protocol

Patients gave informed coherence for the performance of the couple hemodynamic and electrophysiologic studies. In all on the contrary one case, patients underwent baseline hemodynamic and 2D and Doppler echocardiographic evaluation in sinus rhyme Ventricular tachycardia of morphology similar to the patients' clinical VT was then induced by way of programmed electrical stimulation. Repeated hemodynamic and 2D and Doppler echocardiographic assessments were made after VT had been sustained for 10 min. undivided patient underwent echocardiographic evaluation during spontaneous sustained VT and during following sinus rhythm.

Hemodynamic Evaluation

Patients were fasting and lightly sedated with diazepam. Percutaneous Swan-Ganz catheterization was performed from the right femoral vein and left heart catheterization from the right femoral artery with a 7F pigtail catheter. influence measurements from the right atrium, pulmonary artery, pulmonary capillary wedge, left ventricle, and aorta were series of measuresed through fluid-filled Statham transducers linked to a multichannel physiologic recorder (Gould archetype ES1000), with hard copy displayed in succession a multichannel strip chart recorder. Cardiac output determinations were made by way of thermodilution technique. Saturation determinations from the right atrium, pulmonary artery, and systemic circulation were quantified by the agency of oximetry.

Electrophysiologic Study