G. Anguissola

α-Adrenergic Blockade Improves Recovery of Myocardial Perfusion and Function After Coronary Stenting in Patients With Acute Myocardial Infarction

Background—AMI reperfusion by thrombolysis does not improve TIMI flow and LV function. The role of infarct-related artery (IRA) stenosis and superimposed changes in coronary vasomotor tone in maintaining LV dysfunction must be elucidated. Methods and Results—Forty patients underwent diagnostic angiography 24 hours after thrombolysis. Seventy-two hours after thrombolysis, the culprit lesion was dilated with coronary stenting. During angioplasty, LV function was monitored by transesophageal echocardiography. Percent regional systolic thickening was quantitatively assessed before PTCA, soon after stenting, 15 minutes after stenting, and after phentolamine 12 μg/kg IC (n=10), the α1-blocker urapidil 600 μg/kg IV (n=10), or saline (n=10). Ten patients pretreated with β-blockers received urapidil 10 mg IC. Coronary stenting significantly improved thickening in IRA-dependent and in non–IRA-dependent myocardium (from 27±15% to 38±16% and from 40±15% to 45±15%, respectively). Simultaneously, TIMI frame count decre...

Postischemic Left Ventricular Dysfunction Is Abolished by Alpha-Adrenergic Blocking Agents

OBJECTIVES We sought to evaluate the efficacy of alpha-adrenergic blocking agents in counteracting left ventricular (LV) dysfunction occurring after transient ischemia in humans. BACKGROUND The mechanisms underlying postischemic LV dysfunction are largely unknown. METHODS Percutaneous transluminal coronary angioplasty (PTCA) provides a clinical model of ischemia and reperfusion. In 50 patients undergoing coronary stenting for 77+/-5% stenosis, LV function was monitored by transesophageal echocardiography during and 30-min after PTCA. Fifteen minutes after stenting, 15 patients received 12 microg/kg body weight of the alpha-blocker phentolamine intracoronarily, 15 patients received 600 microg/kg of the alpha1-blocker urapidil intravenously, 10 patients received the combination of phentolamine and 1.2 mg of propranolol intracoronarily, and 10 patients received saline. RESULTS Fifteen minutes after successful coronary dilation, significant contractile dysfunction occurred in previously ischemic and nonischemic myocardium. LV dysfunction was accompanied by an increase in coronary resistance and diffuse vasoconstriction. Alpha-blockers counteracted LV dysfunction and coronary resistance and the increase in vasoconstriction. Phentolamine and urapidil increased global LV shortening from 34+/-9% to 45+/-8% and to 49+/-8%, respectively (p < 0.05). After the administration of propranolol combined with phentolamine, LV dysfunction remained unchanged (34+/-6%), as in control subjects. CONCLUSIONS LV dysfunction occurs after PTCA, as described in animal models after ischemia. Alpha-blockers abolished LV, macrocirculatory and microcirculatory dysfunction, whereas the alpha-blocker effect was prevented by combining alpha- and beta-blockers. The evidence of diffuse rather than regional dysfunction, together with the opposite effects of alpha- and beta-blockade, supports the hypothesis of neural mechanisms eliciting postischemic LV dysfunction.

The Alpha-1 Adrenergic Blocking Agent Urapidil Counteracts Postrotational Atherectomy “Elastic Recoil” Where Nitrates Have Failed

Calcium antagonist pretreatment and intracoronary high doses of nitrates (9 mg of isosorbide dinitrate) do not counteract coronary vasoconstriction occurring after rotational atherectomy. In 30 patients undergoing Rotablator atherectomy, intracoronary injection of the alpha 1-sympathetic blocker urapidil abolished or prevented significant vasoconstriction occurring 15 minutes after the procedure despite repeated injections of nitrates.

Impaired bradykinin response to ischaemia and exercise in patients with mild congestive heart failure during angiotensin-converting enzyme treatment : relationships with endothelial function, coagulation and inflammation

Inflammation and endothelial dysfunction play important roles in the pathophysiology of congestive heart failure (CHF), and the peptide bradykinin, generated during inflammation, may act as a defence mechanism by inducing vasodilation. Plasma bradykinin levels are increased in experimental heart failure but low in patients with advanced chronic CHF despite treatment with angiotensin‐converting enzyme (ACE) inhibitors. It is not currently known how bradykinin behaves in less severe phases of CHF controlled by long‐term ACE inhibitor treatment. We studied 10 male patients with clinically stable chronic CHF [New York Heart Association (NYHA) class II] on long‐term ACE inhibitor treatment and 10 normal sex‐ and age‐matched control subjects. High performance liquid chromatography/radioimmunoassay methods were used to evaluate plasma levels of bradykinin in relation to an array of parameters of endothelial function, coagulation and inflammation before and after stimuli of forearm arterial occlusion and physical exercise. CHF patients had higher levels of bradykinin (P = 0·008), activated factor XII (P = 0·049), interleukin‐6 (P = 0·050) and tumour necrosis factor receptor II (sTNFRII) (P = 0·026) than controls. Arterial occlusion and exercise significantly increased bradykinin and von Willebrand factor levels in controls but not in CHF patients. The increase in brachial artery diameter after arterial occlusion was less in CHF patients (P = 0·036) and inversely related to baseline plasma levels of bradykinin (r = −0·855, P = 0·002) and sTNFRII (r = −0·780, P = 0·008). NYHA class II CHF patients during long‐term treatment with ACE inhibitors have increased bradykinin levels and signs of inflammation. They are unable to respond adequately to stimuli of ischaemia and physical exercise which both require vasodilation.