The hemodynamic response to exercise stress was assessed in 17 patients with left ventricular (LV) aneurysm, demonstrated by contrast left ventriculography, and congestive cardiac failure (CCF) before and after sublingual isosorbide dinitrate (ISDN). Radionuclide ventriculography was performed at rest and during exercise in 14 patients. ISDN increased mean exercise LV stroke work index (LVSWI) from 31 to 39 g-m/m2 (p less than 0.001) and reduced mean exercise LV filling pressure from 38 to 25 mm Hg (p less than 0.001). Using the combined criteria of LVSWI and ejection fraction of the contractile section of the left ventricle (EFCS), no patient with rest EFCS of less than 40% achieved a good absolute response to exercise in LV performance with or without ISDN. Of the six patients with rest EFCS greater than or equal to 40% only three achieved a good response. While rest EFCS less than 40% indicates poor LV functional reserve, good LV functional reserve is not always indicated by rest EFCS greater than or equal to 40%.

SUMMARY Seven patients with severe chronic congestive cardiac failure secondary to ischaemic heart disease performed submaximal supine exercise before and after 5 mg sublingual isosorbide dinitrate at the time of cardiac catheterisation. Exercise before isosorbide dinitrate produced a poor response in left ventricular performance. After isosorbide dinitrate this response was significantly improved.Compared with the control exercise period, cardiac index increased from mean 2 6 to 3*1 1/min per m2 (P < 0.0025), stroke volume index from mean 22 to 27 ml/m2 (P < 0 0025), and left ventricular stroke work index from mean 21 to 30 g M/M2 (P < 0.01). Mean left ventricular filling pressure fell from 37 to 26 mmHg (P < 0-01).Although isosorbide dinitrate reduced left ventricular filling pressure at rest from mean 26 to 17 mmHg (P < 0.005), there was no significant change in mean cardiac index or stroke volume index, while left ventricular stroke work index decreased from mean 29 to 22 g M/M2 (P < 0 05).Isosorbide dinitrate effectively reduces left ventricular filling pressure in the resting patient with congestive cardiac failure but produces a more comprehensive improvement in left ventricular performance during exercise.

SUMMARY The haemodynamic effects of dopamine and isosorbide dinitrate alone and in combination were studied in 8 patients with chronic congestive cardiac failure. In 7 patients dopamine, 6,tg/kg per min, increased mean cardiac index from 2-0 to 3 0 1/min per m2 (P < 0.0005); mean stroke volume index from 20 to 27 ml/m2 (P < 0.0025), and mean left ventricular stroke work index from 14 to 20 g M/M2 (P < 0.0025). Mean left ventricular filling pressure did not change significantly. Isosorbide, 5 to 10 mg sublingually, reduced mean left ventricular filling pressure from 29 to 24 mmHg (P < 0.0005) and mean arterial pressure from 80 to 73 mmHg (P < 0 01), with no significant change in mean cardiac index, stroke volume index, or left ventricular stroke work index. When dopamine was reinfused after isosorbide administration mean cardiac index increased to 3 2 1/min per m2, stroke volume index to 31 mu/m2 (P < 0 05 vs dopamine alone), and left ventricular stroke work index to 23 g in/m2(P < 0-0125 vs dopamine alone). Mean left ventricular filling pressure rose slightly to 25 mmHg but this was significantly less than for dopamine alone (P < 0 0005). In an eighth patient, whose left ventricular filling pressure fell to 12 mmHg after isosorbide, the reinfusion of dopamine was associated with severe bradycardia and hypotension, which responded to the intravenous administration of atropine.Afterload reduction with isosorbide combined with inotropic stimulation with dopamine may produce greater improvement in left ventricular performance in patients with congestive cardiac failure than either drug alone. Such treatment should be used with caution possibly in patients whose left ventricular filling pressure falls into the lower range after isosorbide alone.

1 Problems have been encountered in recent years in confirming useful benefit to patients with heart failure and sinus rhythm from acute exposure to digitalis glycosides, though effectiveness of these preparations upon cardiac contractile performance is indisputable. Undesired effects such as those upon systemic vascular resistance have been invoked to explain this. 2 Detailed haemodynamic responses have been studied by cardiac catheterisation in nine such patients for 30 min after intravenous methyldigoxin infusion. Myocardial glycoside uptake was simultaneously assessed. 3 Methyldigoxin uptake by the heart was rapid, passing its peak within 20 min, and was followed by substantial elution. 4 A small progressive and significant increase in cardiac output was observed, though left ventricular filling pressures were not significantly reduced after methyldigoxin. Cardiac contractile function as assessed by left ventricular maximum dP/dt, measured in six patients, showed consistent improvement.

SUMMARY The effects of sodium nitroprusside alone and in combination with phenylephrine were studied at the time of cardiac catheterisation in 10 patients with normal left ventricular function. Nitroprusside was infused to reduce mean arterial pressure in 5 patients with the heart rate free (group 1) and in 5 with the heart rate fixed by atrial pacing (group 2). In group 1 nitroprusside increased heart rate and reduced left ventricular filling pressure and stroke volume. Mean coronary sinus flow increased from 168 ml/min to 187 ml/min, while mean myocardial oxygen extraction fell from 65 to 58 per cent.Mean myocardial oxygen consumption was unchanged. In group 2 nitroprusside reduced left ventricular filling pressure and stroke volume. Mean coronary sinus flow fell from 154 ml/min to 121 ml/min while myocardial oxygen extraction remained unchanged. Mean myocardial oxygen consumption fell from 17 ml/min to 13 ml/min. Phenylephrine restored mean arterial pressure with associated bradycardia in group 1. Left ventricular filling pressure and stroke volume were restored in both groups. In group 1 phenylephrine produced no further changes in mean coronary sinus flow or myocardial oxygen extraction. In group 2 phenylephrine increased mean coronary sinus flow from 121 ml/min -to 173 ml/min and increased mean myocardial oxygen consumption from 13 ml/min to 19 ml/min, myocardial oxygen extraction remaining constant. Nitroprusside is a coronary vasodilator but this action may be counteracted by changes in heart rate or afterload.Sodium nitroprusside has been shown to produce haemodynamic improvement in patients with congestive cardiac failure after acute myocardial infarction (Franciosa et al., 1972;Chatterjee et al., 1973;Parmley et al., 1974