Progressive Deterioration Of Left Ventricular Function Research Articles

Noninvasive MR characterization of structural and functional components of reperfused infarct

left ventricular (LV) remodeling is a highly complex phenomenon that starts soon after infarction and progresses to extensive regional and global architectural changes over time. to noninvasively comprehensively characterize transient (edema, hemorrhage, microvascular obstruction (MO)) and persistent structural (infarct size) components of reperfused infarct up to 10 weeks and to determine their relation to LV function. farm pigs were used for the study. Under fluoroscopy the left anterior descending (LAD) coronary artery was occluded for 90 min. MR imaging was performed at 3 days (n=14 pigs), 5 weeks (n=10), and 10 weeks (n=6) after reperfusion. The following MR imaging sequences were used: (i) cine; (ii) T2-weighted turbo spin echo; (iii) T2*-weighted turbo spin echo; (iv) tagged; (v) phase-contrast velocity-encoded; (vi) first-pass perfusion; and (vii) delayed contrast-enhanced (DE-MR imaging). After imaging, animals were euthanized at 3 days (n=4), 5 weeks (n=4), and 10 weeks (n=6) and hearts were stained with triphenyltetrazolium chloride to define acute, subacute, and scar infarct and interstitial hemorrhage. T2, T2*, and DE-MR imaging demonstrated transient interstitial edema, interstitial hemorrhage, and MO, respectively. MO was observed in 85% of animals and 60% of these showed hemorrhages. Cine, tagged, and phase-contrast velocity-encoded images documented the persistent impairment in 3D strain of infarcted segments, which on first-pass perfusion showed persistent perfusion deficit. MR imaging demonstrated the progressive increase in LV volumes and decreased ejection fraction over time. The changes in LV between 5 and 10 weeks were not related to the presence of interstitial edema, interstitial hemorrhage, MO or increase in infarct size. the various MR sequences described in this study allowed the demonstration of transient and persistent components of reperfused infarct. The progressive deterioration of global LV function was not related to the transient reperfusion components (edema, hemorrhage or MO) or change in infarct size. The results imply that MR imaging has the potential to identify progressive deterioration of LV function unrelated to reperfusion injury components or infarct size.

Left ventricular function during exercise testing and training

Left ventricular function (LVEF) deteriorates during incremental exercise (GXT) in patients with ischemia (+ISCH). Left ventricular (LV) functional response during steady-state exercise, typical of that used in exercise training, are unknown. We compared LVEF in patients with documented coronary heart disease (CHD) who either had (+) or did not have (-) ISCH, and in healthy volunteers (CONTROL) during GXT and steady state. First pass RNA was performed during upright cycle GXT at rest (R), at the ventilatory threshold (VT), and at maximal exercise (Max); and during steady state at the workload associated with VT after 10, 20, and 30 min of exercise. RNA allowed measurement of ejection fraction (EF) and wall motion (WM); ISCH was mild, angina being relieved by momentary reductions in workload during steady state. Although +ISCH demonstrated the expected deterioration in LV function during GXT (decreased EF, abnormal WM)(EF = 58 to 56 to 54%), there was no evidence for progressive deterioration of LV function during steady state despite the presence of mild ISCH (56 to 56 to 54 to 54%). In -ISCH and CONTROL there were normal responses of EF during GXT (43 to 51 to 51% and 59 to 65 to 61%) and steady state (43 to 51 to 53 to 51% and 59 to 65 to 68 to 69%). We conclude that mild ischemia may be tolerated during steady-state exercise at levels consistent with exercise training without progressive deterioration of LV function.

978-121 Ventricular Function During Exercise Testing and Training

Left ventricular (LV) function deteriorates during incremental exercise (GXT) in pts with ischemia (ISCH). Responses during steady state (SS) exercise, typical of that used in exercise training, are unknown. We compared LV function in pts with documented CHD who either had (+) or did not have (–) ISCH. First pass RNA was performed during upright cycle GXT (Rest. ventilatory threshold (VT). & Max) and SS at VT (20, 30 min). RNA allowed measurement of ejection fraction (EF). end diastolic (EDV), end systolic volume (ESV) and stroke volume (SV). ISCH was mild, angina being relieved by momentary reductions in workload during SS. Results in –/+ ISCH: GXT SS Rest VT Max 20’ 30’ HR 68/73 118/130 160/153 134/135 146/142 EF 52/54 59/51 57/49 61/50 61/52 EDV 176/147 203/153 210/175 195/153 181/146 ESV 86/72 85/80 94/95 85/77 78/73 SV 91/75 118/73 116/80 117/76 108/73 Although +ISCH demonstrated the expected deterioration of LV function during GXT (decreased EF, increased ESV, unchanged SV). there was no evidence for progressive deterioration of LV function during SS despite the presence of mild ISCH. We conclude that mild ischemia may be tolerated during relatively prolonged SS exercise without progressive deterioration of LV function.

Left ventricular function in end-stage renal disease: echocardiographic classification.

We used echocardiography (ECHO) to detect pericardial effusions and assess left ventricular (LV) function in 39 patients with end-stage renal disease (ESRD). Pericardial effusions were present in 24 patients (62%). Thirty-one patients (79%) had concentric hypertrophy and 20 patients (51%) had decreased LV compliance. The majority of patients with concentric hypertrophy and decreased LV compliance had normal LV internal dimensions and contractility. Six patients (15%) had ECHO results compatible with congestive cardiomyopathy. An echocardiographic distinction between congestive heart failure, decreased LV compliance, and salt and water overload in ESRD has allowed an appropriate therapeutic decision as to whether to administer cardiac glycosides or increase ultrafiltration as a treatment for pulmonary congestion. ECHO is a safe, convenient, and noninvasive method of assessing serial LV function, and it can be used to document progressive deterioration of LV function in ESRD.