Effects of the AT1-selective angiotensin II antagonist, telmisartan, on hemodynamics and ventricular function after cardiopulmonary resuscitation in pigs.

The purpose of this study was to investigate the effects of the angiotensin II (ANG II) antagonist, telmisartan, on hemodynamics, myocardial function and myocardial blood flow during the postresuscitation phase in a porcine model of CPR and to compare these to saline. After 4 min of ventricular fibrillation and 5 min of closed-chest CPR, defibrillation was performed in 16 domestic pigs to restore spontaneous circulation (ROSC). Ten minutes after ROSC, animals were allocated to receive either the ANG II antagonist, telmisartan, at a dose of 1 mg/kg (n = 8) or saline (n = 8). Hemodynamics, myocardial function and myocardial blood flow were measured prearrest and at 5, 30, 90 and 240 min after ROSC. Using a Swan-Ganz catheter with a fast responding-thermistor and a micromanometer tipped catheter, right ventricular end-diastolic and end-systolic volume, right ventricular ejection fraction, left ventricular contractility were 67 +/- 6 ml (mean +/- S.E.M.), 42 +/- 4 ml, 38 +/- 2%, 2036 +/- 77 mmHg/s in the telmisartan group and 82 +/- 2 ml (P < 0.05), 59 +/- 3 ml (P < 0.01), 28 +/- 2% (P < 0.01), 1596 +/- 82 mmHg/s (P < 0.01) in the control group, at 240 min after ROSC. No significant differences in mean aortic and pulmonary artery pressure, cardiac index or myocardial blood flow between the two groups were found. We conclude that the ANG II antagonist telmisartan administered during the postresuscitation phase in pigs increases myocardial contractility without changing cardiac index, systemic vascular resistance, pulmonary vascular resistance, or myocardial perfusion.