Abstract
Alpha human atrial natriuretic polypeptide (α-hANP) was intravenously infused into 7 patients with ischemic heart disease who had almost normal cardiac function at a rate of 0.025 μg/kg/min for 15 min. During infusion of α-hANP, left ventricular (LV) systolic pressure decreased from 144 ± 19 (SD) to 129 ± 22 mmHg (p < 0.01), LV end diastolic pressure (EDP) from 15 ± 5 to 13 ± 4 mmHg (p < 0.05), mean aortic pressure from 102 ± 14 to 91 ± 14 mmHg (p < 0.01), time constant of LV pressure fall (T) from 100 ± 15 to 88 ± 13 msec (p < 0.05), systemic vascular resistance (SVR) from 1711 ± 206 to 1424 ± 340 dynes·sec·cm-5 (p < 0.05) and coronary vascular resistance (CVR) from 8.5 ± 1.2 to 7.4 ± 1.3 × 104 dynes·sec·cm-5 (p < 0.05). There was a linear correlation between percent changes in SVR and those of CVR (r=0.92, p < 0.01), and the fall in CVR was approximately 68% of that in SVR. Increases occurred in heart rate from 63 ± 7 to 66 ± 8 beats/min (p < 0.05), LV dp/dt from 1558 266 to 1627 238 mmHg/sec (p 0.05), LV dp/dt/p from 22.9 3.2 to 25.6 3.7/sec (p 0.01), and myocardial oxygen consumption (from 7.9 2.4 to 9.8 2.1 ml/min, p 0.05), while mean right atrial and mean pulmonary arterial pressures and pulmonary vascular resistance were unchanged. -hANP dilates the systemic and coronary resistance vessels, and increases myocardial shortening velocity and relaxation.
