Peter Hairston

Myocardial Contractile Force as Influenced by Direct Coronary Surgery

Abstract Myocardial contractile force (MCF) measured by direct application of a strain-gauge arch to the left ventricular surface was determined intraoperatively in 11 patients having saphenous vein graft (SVG) bypass of acute or chronic coronary arterial obstruction. The MCF determinations with the grafts open (control), occluded, and released demonstrated a consistent reduction (average 31%) in contractility during graft occlusion and a prompt return to control levels following graft release without alteration in other aspects of ventricular function. Similar changes were not observed during graft occlusion if the arch was applied to nonviable (scarred) myocardium or to areas outside the region of graft perfusion. The SVG augmentation of blood flow to acute or chronically ischemic but viable myocardium enhances MCF or isometric systolic tension, from which coincident improvement in ventricular function should be anticipated.

An Improved Method for Collection of Shed Mediastinal Blood for Autotransfusion

Abstract A standard method for collection of shed mediastinal blood has been modified to incorporate underwater-seal drainage and manometer-controlled suction through the chest catheter. This method is useful for autotransfusion of shed mediastinal or thoracic blood following cardiac surgical procedures.

Flow in Coronary Artery Bypass Grafts to Totally and Partially Occluded Left Anterior Descending Coronary Arteries

Flow was determined by electromagnetic flowmeter in vein bypass grafts in 20 patients with a totally occluded left anterior descending (LAD) coronary artery and on 61 patients with a partially occluded LAD. The median flow in LAD grafts was 14.5 ml/min with total LAD occlusion, and 40 ml/min with partial LAD occlusion (p less than 0.001). In cases of total LAD occlusion, the presence of mild or moderate anteroseptal wall dysfunction was associated with more satisfactory flow than was the case with severe anteroseptal wall dysfunction (p less than 0.02). Flows over 25 ml/min were found only when the LAD distal to total occlusion was 1.5 mm or greater. Unsatisfactory flows were consistently found with total LAD occlusion, poor ventricular function, and a distal LAD less than 1.5 mm. Repeat catheterizations to determine an unsatisfactory patency rate under these conditions would be necessary to alter our policy of grafting all suitable vessels beyond a total occlusion.

Application of Multivariate Analysis to the Enzyme Patterns in the Serum of Patients Undergoing Coronary Artery Operation

Serial determinations of serum glutamic oxaloacetic transaminase, lactic dehydrogenase, and creatine phosphokinase were performed in 50 consecutive patients undergoing cardiac operation for coronary artery bypass or combined valve replacement and coronary artery bypass. Thirty-seven patients (74%) who demonstrated minimal or no changes on the electrocardiogram manifested a recognizable pattern of distribution of the enzyme sequences. The pattern of these patients served as controls for the detection of abnormal patterns. All other patients were grouped together, regardless of clinical behavior. Perioperative myocardial infarction was established in 5 patients (10%) and resulted in 1 death. The purpose of this study was to apply discriminant analysis to two clinically determined patient groups in order to ascertain whether the three enzyme readings can be used to classify patients into their respective groups. The results suggest that enzyme profiles reflect degrees of myocardial damage that can serve to identify clinical infarction.

Use of Indwelling Shunt in Second-Side Carotid Endarterectomy: Help or Hazard

A retrospective study of three hundred and twenty consecutive patients operated upon between 1969 and 1979 who had successfully undergone a one-side carotid endarterectomy was undertaken in order to help assess the influence of shunting or nonshunting on the results obtained following their second-side endarterectomy. Two hundred and thirty-five patients underwent endarterectomy with an inlying shunt and eighteen suffered a neurologic deficit (7.6%) while eighty-five underwent endarterectomy without a shunt with two neurologic deficits (2.3%). Carotid clamp time had no influence on outcome.