DiVerent eVects of abnormal activation and myocardial disease on left ventricular ejection and filling times
نویسندگان
چکیده
Background—Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific eVects on timing remain undetermined. Objective—To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the eVects of abnormal activation from those of cavity dilatation. Methods—Subjects were 20 normal individuals, 11 patients with isolated left bundle branch block (LBBB, QRS duration > 120 ms), 17 with dilated cardiomyopathy and normal activation, and 23 with dilated cardiomyopathy and LBBB. An additional 30 patients (nine with normal ventricular systolic function and 21 with dilated cardiomyopathy) were studied before and after right ventricular pacing. Left ventricular ejection and filling times were measured by pulsed wave Doppler and cavity size by M mode echocardiography. Results—Z ratio was independent of RR interval in all groups. Mean (SD) Z ratio was 82 (10)% for normal subjects, 66 (10)% for isolated LBBB (p < 0.01 v normal), 77 (7)% for dilated cardiomyopathy without LBBB (NS v normal), and 61 (7)% for dilated cardiomyopathy with LBBB (p < 0.01 v normal). In the nine patients with normal left ventricular size and QRS duration, Z ratio fell from 88 (6)% in sinus rhythm to 77 (10)% with right ventricular pacing (p = 0.26). In the 21 patients with dilated cardiomyopathy and LBBB, Z ratio rose from 59 (10)% in sinus rhythm to 74 (9)% with right ventricular DDD pacing (p < 0.001). Conclusions—Z ratio dissociates the eVects of abnormal ventricular activation and systolic disease. It also clearly diVerentiates right ventricular pacing from LBBB. It may thus be useful in comparing the haemodynamic eVects of diVerent pacing modes in patients with or without left ventricular disease. (Heart 2000;84:272–276)
منابع مشابه
Doppler-Derived Myocardial Performance Index in Healthy Children in Shiraz
Background: Assessment of myocardial function is essential in heart disease, but in regard to systolic and diastolic functions such evaluation has limitation. Ejection fraction is difficult to assess in abnormally-shaped ventricles, and diastolic inflow velocity pattern may be fused because of tachycardia. Objective: A myocardial performance index (MPI) or Tei index has been developed for adult...
متن کاملDifferent effects of abnormal activation and myocardial disease on left ventricular ejection and filling times.
BACKGROUND Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific effects on timing remain undetermined. OBJECTIVE To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the effects of abnormal activation from those of cavity dilatation. METHODS Subjects were 2...
متن کاملThe Correlation between Left and Right Ventricular Ejection Fractions in Patients with Ischemic Heart Disease, Documented by Cardiac Magnetic Resonance Imaging
Introduction: The correlation between right and left ventricular ejection fractions (RVEF and LVEF, respectively) has been studied in only a small number of patients with a marked decrease in RVEF and LVEF. The aim of the present study was to compare LVEF and RVEF in patients with ischemic heart disease. RVEF and LVEF were measured by Cardiovascular Magnetic Resonance (CMR) imaging. Materials a...
متن کاملThe effect of eight weeks of moderate-intensity endurance training on myocardial capillary density, ejection fraction and left ventricular shortening fraction in male rats with myocardial infarction
Background and objective: Vascular obstruction and impaired blood flow and oxygen delivery cause a myocardial infarction and limit a personchr('39')s function. Therefore, finding a way to create new arteries and replace blocked arteries has always been of interest to researchers, including exercise physiologists. Therefore, this study was conducted to evaluate the effect of eight weeks of moder...
متن کاملThe role of oral dipyridamole stress gated SPECT in assessing the response of the left ventricle to stress: Re-evaluation of an old method
Introduction: We aimed to assess whether the vasodilator effect of oral dipyridamole on the left ventricular systolic function in patients with suspected CAD is different from that of intravenous (IV) dipyridamole using Tc-99m MIBI myocardial perfusion gated SPECT. Methods: Eighty-nine patients (17 M / 72 W; 61 ± 10 years) were enrolled in this study. The patients underwent a dipyridamole stre...
متن کامل