ABSTRACT
Nitroglycerin is known to affect the electrophysiological properties of the ischaemic ventricle, possibly by altering regional myocardial blood flow. This study correlated the effects of nitroglycerin, given after acute coronary occlusion, on regional ventricular refractoriness and regional myocardial blood flow. Nitroglycerin returned ventricular refractory periods to their pre-occlusion values in spite of no significant effect on regional myocardial blood flow. Although the beneficial electrophysiological effects of nitroglycerin were not explained by increased regional flow to the ischaemic myocardium, an improved myocardial oxygen supply-demand balance may have produced these favourable effects. This study emphasises the need for electrophysiological evaluation of the effects of interventions intended to limit infarct size.
Subject(s)
Coronary Circulation/drug effects , Coronary Disease/physiopathology , Heart/physiopathology , Nitroglycerin/pharmacology , Animals , Coronary Disease/drug therapy , Dogs , Electrocardiography , Heart/drug effects , Heart Conduction System/drug effects , Heart Conduction System/physiopathology , Heart Ventricles/drug effects , Heart Ventricles/physiopathology , Nitroglycerin/therapeutic useABSTRACT
Twenty-seven consecutive patients with an aortic valve prosthesis were evaluated with retrograde left ventricular catheterization. The prosthesis was successfully crossed, permitting hemodynamic and angiographic evaluation of function of the prosthetic valve, left ventricle and mitral valve in all 27 cases. No complications were encountered. In patients with active endocarditis or recent embolization, the retrograde technique was avoided when possible, and attempts were made to utilize other techniques for study. However, three such patients were evaluated with the retrograde technique without complication. Examination of pressure tracings and cineangiographic films suggested only minor interference with valve poppet movement induced by the catheter transversing the valve. In three cases, hemodynamic data were recorded with the catheter crossing the prosthesis at one time and a paraprosthetic valve defect at another time. Identical gradients were recorded. This series documents the safety and efficacy of the retrograde approach, which is proposed as an alternative to the transseptal technique and left ventricular puncture.
