[Hemodynamic response to high-dose nitroglycerin infusion in patients with severe heart failure after pretreatment...

It is a common opinion that the use of nitrates may have a harmful effect on cardiac output (CO) in patients (pts) with congestive heart failure (CHF) due to left ventricular (LV) dilatation and systolic dysfunction in whom previous treatment with diuretics and vasodilators considerably reduced LV filling pressure. The aim of the present study was to evaluate the effects on CO and LV filling pressure of high dose intravenous nitroglycerin (NTG) in eight pts with dilated cardiomyopathy and with CHF in functional class IV NYHA; they had previously undergone intensive treatment with diuretics and vasodilators, and at the time of the study were in stable clinical conditions. Hemodynamic monitoring was performed by Swan-Ganz catheterization and CO was determined by thermodilution. NTG was administered at increasing doses (maximal doses 350 +/- 220 microgr./m, range 100-800 microgr./m) until systolic arterial pressure (BPs) less than or equal to 85 mmHg and/or pulmonary capillary wedge pressure (PCWP) less than or equal to 4 mmHg. Our results showed that NTG caused a significant reduction of right atrial pressure (RAP, 4 +/- 3.5 vs -1 +/- 4 mmHg, p less than 0.001), systolic pulmonary artery pressure (36 +/- 8 vs 21 +/- 11 mmHg, p less than 0.001) and PCWP (16 +/- 5 vs 7 +/- 3 mmHg, p less than 0.001). LV transmural pressure (TMP) calculated as the difference between PCWP and RAP, showed a nonsignificant reduction from 12 +/- 5 to 8 +/- 3.75 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)