Assessment of cardiac risk before peripheral vascular surgery: a comparison of myocardial perfusion imaging and long axis echocardiography at rest

Circumferential Versus Longitudinal Systolic Function in Patients with Hypertension: A Nonlinear Relation

BACKGROUND

Depressed circumferential midwall performance and impaired left ventricular (LV) longitudinal function are both early markers of LV systolic dysfunction in patients with hypertension. The relation between midwall and longitudinal indices in these patients has never been analyzed.

METHODS

In 126 patients with hypertension, midwall fractional shortening (mFS), stress-corrected mFS, M-mode left atrioventricular plane displacement, and tissue Doppler-derived peak mitral annular systolic velocity were determined.

RESULTS

Regression analysis showed that the relations of midwall indices to atrioventricular plane displacement and mitral annular systolic velocity were all nonlinear. Reductions in atrioventricular plane displacement or mitral annular systolic velocity within their higher ranges corresponded to relatively smaller decreases in mFS and stress-corrected mFS. Relative wall thickness was the strongest determinant of the relative efficiency of circumferential and longitudinal LV contraction.

CONCLUSION

The relation between circumferential midwall and longitudinal function in patients with hypertension is nonlinear and dependent on LV geometry. In these patients, systolic impairment occurs earlier in longitudinal than circumferential performance.

Cardiac pumping capability in patients with peripheral vascular disease

INTRODUCTION

Peripheral vascular disease (PVD) is a condition characterized by atherosclerotic occlusive disease of the lower extremities, low functional capacity and low exercise tolerance. Less empirical data are available concerning the cardiovascular response to maximum exercise tests in patients with PVD. The purpose of this study was to examine cardiovascular variables in patients with peripheral vascular disease.

METHODS

Fifty patients (67 +/- 9 years) completed an incremental exercise test (2 min stages, 3.2 km h(-1), with increases of 2% every 2 min) to maximum claudication pain. Maximal oxygen consumption (VO2) was assessed on a breath-by-breath basis by online expiratory gas analysis (CardiO2, Medical Graphics Co.). Blood pressure was recorded at peak exercise. Following a 30-min rest period, patients exercised at the highest level attained during the first test and cardiac output (QT) was measured using the exponential non-invasive rebreathing method. Cardiac power output peak (CPOpeak) in Watts (W), was then computed.

RESULTS

Mean +/- SD values were; 13.85 +/- 4.14 ml kg min(-1); maximal walk time 357 +/- 227 s; peak mean arterial pressure 127 +/- 15 mmHg; 9.8 +/- 2.39 (l min(-1)); CPO 2.86 +/- 0.87 W.

CONCLUSION

Patients with peripheral vascular disease demonstrate attenuated levels of cardiovascular capacity. This group of patients should be given exercise therapy in order to improve cardiovascular status and ambulatory function.