title: Nature of heart failure in patients with ventricular septal defect.
abstract: To assess the contributions of systolic and diastolic dysfunction to congestive heart failure (CHF) in ventricular septal defect (VSD), we studied 13 children with VSD at catheterization using a Millar catheter. Eight children had CHF, whereas five did not. Phenylephrine was infused at a rate of 5 micrograms.kg-1.min-1, and M-mode echocardiography and pressure were measured simultaneously. Systolic left ventricular (LV) function was assessed by maximum LV pressure (LVP), rate of pressure development (dP/dt), and by the end-systolic pressure-diameter relation (ESPDR). Systolic myocardial function was assessed by the end-systolic stress-strain relation. Diastolic chamber function was assessed by the isovolumic relaxation time constant (tau) and by the end-diastolic pressure-diameter relation (EDPDR). Diastolic myocardial function was measured by the end-diastolic stress-strain relationship. With phenylephrine, maximum LVP increased from 99 +/- 5 to 119 +/- 4 mmHg with CHF and from 106 +/- 6 to 149 +/- 10 mmHg without CHF. +dP/dt was lower with CHF (1,582 +/- 96 mmHg/s) than without CHF (2,300 +/- 200 mmHg/s). The maximum slope of the ESPDR was 39 +/- 8 with CHF and 94 +/- 14 mmHg/cm without CHF. The maximum slope of the midwall stress-strain relation was 223 +/- 37 with CHF and 395 +/- 93 g/cm2 without CHF. tau was 25 +/- 2 without CHF compared with 32 +/- 3 ms with CHF. The EDPDR was shifted leftward with failure, whereas the stress-strain relation was similar for all patients. CHF in patients with VSD results primarily from systolic dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D006328:Cardiac Catheterization; D002303:Cardiac Output, Low / Q000209:etiology* / Q000503:physiopathology*; D003187:Compliance; D003971:Diastole; D005260:Female; D006321:Heart / Q000187:drug effects / Q000503:physiopathology; D006345:Heart Septal Defects, Ventricular / Q000150:complications*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D013599:Systole
chemical_list: D010656:Phenylephrine