Myocardial protection: a safe cardioplegic catheter.

The administration of cold cardioplegic solution has contributed to the "safe" time allowable for performance of intricate cardiac procedures under ischemic arrest. A catheter has been designed that delivers a large bolus of solution quickly, ensures rapid arrest of cardiac function, and allows continuous perfusion during the procedure. It permits the safe escape of air on reestablishment of cardiac function. The catheter can be inserted and removed through a small aortotomy, thereby preventing undue trauma to a sclerotic or thickened aorta.

Intraoperative application of intraaortic balloon counterpulsation determined by clinical monitoring of the endocardial viability ratio.

Persistent unrecognized subendocardial ischemia with development of subendocardial necrosis is a major cause of patient death following cardiopulmonary bypass. The lesion is caused by a discrepancy between the oxygen needs of subendocardial muscle and the available blood supply. If sole reliance is placed upon monitoring conventional vital signs, the more subtle factors contributing to decreased blood flow may go unrecognized. Reported studies have confirmed that the adequacy of subendocardial perfusion can be predicted by calculating the supply/demand ratio, defined as the ratio of the diastolic pressure-time index (DPTI) divided by the systolic pressure-time index (TTI). An analog computer was designed and built that measures the area under the systolic and diastolic component, calculates the DPTI/TTI ratio, and digitally displays the result as the endocardial viability ratio (evr). The EVR was used to determine the adequacy of left ventricular subendocardial blood flow in 64 consecutive patients undergoing cardiac operations. Unidirectional intraaortic balloon counterpulsation (IABC) was utilized in 14 patients with 9 long-term survivors. The difference in mean EVR between survivors and nonsurvivors at the initiation of balloon support was statistically significant. Early application of unidirectional IABC when subendocardial ischemia persists following open cardiac procedures may prevent deterioration to subendocardial necrosis with subsequent morbidity or mortality.

Definitive diagnosis of pulmonary lesions in leukemia and lymphoma. The supportive role of thoracic surgery.

As therapy for leukemia and lymphoma has improved, secondary pulmonary disease has become a major cause of death. In this review of 225 patients with leukemia or lymphoma, six possibly preventable deaths resulted because progressive pulmonary infiltrates were treated without tissue diagnosis. Four other patients died of undiagnosed second primary lung tumors. When pulmonary infiltrates were diagnosed by open lung biopsy examination, appropriate therapy in nine patients resulted in seven survivals from potentially lethal infections. Of six patient with either primary lung tumor, leukemic infiltrate, or lymphomatous nodule, bronchoscopy and brush biopsy examination revealed bronchogenic tumors, leading to appropriate surgical therapy and survival in three. In three others, bronchoscopy and mediastinoscopy suggested exacerbation of the primary disease, which was treated satisfactorily by radiotherapy. Thus, when pulmonary disease develops in patients with leukemia or lymphoma, aggressive therapy based on tissue diagnosis may avert untimely death.

A clinical method for detecting subendocardial ischemia after cardiopulmonary bypass.

Subendocardial ischemia with consequent subendocardial necrosis is a frequent cause of death after cardiopulmonary bypass. The problem is caused by an inequity in the oxygen requirements of the subendocardium and the available blood supply. We have developed a means of detecting ischemia early in the postperfusion period. Using an analogue computer, we determine the endocardial viability ratio (EVR). This value may decrease before either systemic or central venous pressure changes. Thus the ratio can reflect early the danger of subendocardial ischemia. Another advantage is that equipment now common in coronary care units can be used to determine the EVR.