Current status of intra-aortic balloon counterpulsation in critical care cardiology.

Retrospective analysis revealed that intra-aortic balloon counterpulsation was attempted in 321 patients at our institute from August 1, 1974, to July 1, 1982. The intra-aortic balloon pump (IABP) was successfully inserted in 298 cases (93%). Indications for an IABP included: cardiogenic shock (84 cases), preoperative hemodynamic coverage (15 cases), low-output syndrome (73 cases), pre- and postinfarction angina (75 cases), intractable congestive heart failure (12 cases), refractory ventricular arrhythmia (9 cases), percutaneous transluminal coronary angioplasty (14 cases), cardiac arrest (7 cases), and a miscellaneous group (9 cases). The overall major complication rate was 9%. The data from this experience support aggressive management of cardiogenic shock, i.e., early balloon insertion, angiography, and cardiac surgery, which significantly increases the survival rate (83%) over medical therapy combined with balloon counterpulsation alone. The IABP was also extremely effective in managing other high-risk categories when combined with some form of definitive mechanical correction, e.g., coronary revascularization, valve replacement, or percutaneous transluminal coronary angioplasty. Left ventricular (LV) function was a significant indicator of long-term survival in our series. Patients with normal or moderately impaired LV function had higher survival rates (95% and 82%, respectively) than patients with poor LV function (42%).

The role of intra-aortic balloon counterpulsation in patients undergoing percutaneous transluminal coronary angioplasty.

Between June, 1979, and July, 1982, 14 patients required an IABP in conjunction with PTCA. The clinical indications for balloon counterpulsation, in the performance of PTCA were (1) clinically unstable situations where PTCA might otherwise be contraindicated, e.g., left main stem disease, multivessel coronary artery disease, unstable anginal syndromes, and cardiogenic shock; (2) preoperative insertion of an IABP for added safety following unsuccessful angioplasty; (3) abrupt vessel closure during a PTCA procedure in which the patient becomes hemodynamically unstable; and (4) late vessel closure following an initially successful angioplasty resulting in hemodynamic compromise. Of the 14 cases requiring balloon counterpulsation, 13 survived hospitalization and were alive at the time this report was submitted. We conclude that IABP is a useful adjunct to PTCA in a variety of clinical circumstances.

Evaluation of a rechargeable pacemaker system.

A rechargeable-demand nickel-cadmium pulse generator for permanent transvenous cardiac pacing was evaluated in 66 patients. During a cumulative follow-up period of 2,333 patient months (194.4 patient years), failure of the pacing circuit occurred in 3 patients at 21, 25, and 27 months, respectively. Nine patients had difficulty accepting the recharging concept and, in 3 of these patients, it became necessary to replace the rechargeable generator with a conventional energy source. The overall failure rate of approximately 3% per year (including the 3 patients in whom it was necessary to remove the generator because of failure to recharge properly), coupled with the inconvenience of recharging, limits the usefulness of the rechargeable system compared to the newer lithium-powered generator.

Reduced incidence of intraoperative myocardial infarction during coronary bypass surgery with use of intracoronary shunt technique.

Intraoperative myocardial infarction is a recognized complication of aortocoronary bypass surgery. One major cause of such infarction may be interruption of coronary blood flow, particularly in patient with poor coronary collateral circulation. In 30 patients use of an intracoronary shunt made it possible to limit the period of coronary occulusion during graft construction to a few minutes. Use of this shunt was associated with a reduced incidence of intraoperative myocardial infarction (as judged by the appearance of new Q waves) when these patients were compared with 50 patients operated on without this procedure (6 of 50 [12 percent] versus 0 of 30). The incidence of postoperative persistent S-T segment elevation was reduced from 21 of 50 (42 percent) to 5 of 30 (17 percent). Except for use of the shunt, the surgical technique was identical in the two groups of patients.

Right ventricular apexangiography for precise placement of transvenous electrode catheters.

A simple angiographic technique (right ventricular apexangiography) for positioning permanent transvenous pacemakers is described. With this technique, electrode failure occurred in only five (3%) of 186 patients followed for more than two years, as compared to an average failure rate of 23% in 11 reported series. Right ventricular apexangiography should be particularly useful in those patients in whom problems arise during insertion of a permanent transvenous electrode catheter.

Incidence and implications of abnormal intraventricular conduction in the coronary care unit.

A transient, intermittent, or permanent disorder of intraventricular conduction was found in 35% of 404 patients with acute myocardial infarction. Patients with acute myocardial infarction and abnormal intraventricular conduction were older than patients with normal intraventricular conduction, but there was no significant age difference between patients with normal and abnormal intraventricular conduction who died. Mortality was only slightly higher in patients with preexisting intraventricular conduction disorder than in patients with normal intraventricular conduction. On the other hand, mortality was remarkably higher in patients in whom abnormal intraventricular conduction developed during the course of acute myocardial infarction than in patients with either normal intraventricular conduction or preexisting abnormal intraventricular conduction. Transvenous cardiac pacing had little impact on mortality, death being due to pump failure in the majority of the patients. This study identifies a group of high-risk patients in whom early aggressive management utilizing newer therapeutic modalities such as mechanical circulatory assistance, emergency aortocoronary bypass, or both, might be profitably applied.

Early evaluation of a rechargeable pacemaker system.

A rechargeable demand pulse generator for permanent transvenous cardiac pacing was evaluated in 66 patients. During a cumulative follow-up period of 895 patient months there was no instance of failure of either the pulse generator or of the recharging circuit. Acceptance of the recharging concept was high, there being only one patient in whom it was necessary to replace the rechargeable generator because of inability to master the recharging technique. The early findings indicate that with proper patient selection the rechargeable pulse generator promises to be an important contribution to pacemaker therapy.