Effects of pulsatile and nonpulsatile coronary perfusion on performance of the canine left ventricle.

This study compares the effect of pulsatile (Group C, Fib/P) and nonpulsatile (Group B, Fib/NP) coronary perfusion on myocardial performance during 2 hours of normothermic ventricular fibrillation. Group A (BH/NP), used as a base-line observation, consisted of 2 hours of nonpulsatile coronary perfusion in beating hearts. The assessment of ventricular performance included diastolic ventricular compliance, myocardial oxygen consumption and lactate extraction, regional myocardial blood flow, and histology. After 120 minutes of ventricular fibrillation, Group C showed normal ventricular diastolic compliance as compared to a 50 per cent decrease in Group B (p less than 0.01). Myocardial oxygen consumption was not significantly different from that in Group B. Because of a 70 per cent increase in oxygen extraction above Group B (p less than 0.05), total left ventricular myocardial blood flow was reduced (103 +/- 23 versus 260 +/- 36 ml. per 100 Gm. per minute, p less than 0.05) and had near-constant resistance. Lactate extraction was significantly greater and more stable as compared to Group B (9.28 +/- 1.33 versus 1.8 +/- 1.08, p less than 0.05). Left ventricular endocardial/epicardial flow ratio was greater in Group C (1.21 +/- 0.08 versus 1.06 +/- 0.06, p less than 0.05). Minimal subendocardial histologic changes were present as compared to the marked patchy subendocardial ischemic changes seen in Group B. The results demonstrate that the addition of pulsatile flow to coronary perfusion minimized the deleterious effects of prolonged ventricular fibrillation on myocardial performance.

Training in microvascular surgery.

This is the first report that analyzes the time required for a general surgeon to master the technique of anastomosis of arteries with diameters of 1.25 and 1.5 mm. Probes of 0.25 mm gradation were used to calibrate the lumens of the arteries and the anastomoses. The Zeiss microscope was used at 25 magnifications to repair a transverse division of the abdominal aorta of a 120 gram rat. Fifteen hours were required for the surgeon (S.H.) to become accustomed to the use of the equipment. Then a series of 40 rats were operated upon and kept alive from 1 to 6 weeks. Patency rate was 100% (40 of 40). No anastomosis was less than 1.25 mm in diameter. After the initial practice period of 15 hours, quality of anastomosis was unchanged, but time required to perform it diminished from 45 minutes to 15 minutes during the course of 40 procedures that occupied 35 laboratory hours.

Combined left ventricular aneurysm and coronary artery bypass surgery: long-term results of 100 consecutive patients.

Forty-four percent of 2,367 patients who had operations for the complications of coronary atherosclerosis between 1971 and 1977 were noted to have major left ventricular wall motion abnormalities. Of this group, 100 patients required left ventricular aneurysm resections or plications (4.2%). There were 85 men and 15 women. Their average age was 52 years (range, 30 to 68 years). Concomitant coronary artery bypass grafting was required in 95 patients. The operative mortality was 7% and the actuarial survival at six years was 78%. Patients were followed for an average of 31 months (range, 3 to 72 months). Eighty-eight percent of the survivors had excellent or good results with improvement of their functional status to the New York Heart Association classes I and II. Age, congestive heart failure, and poor residual left ventricular function had an adverse effect on the outcome of these patients. Concomitant coronary artery bypass grafting seems to have favorably influenced their outcome and functional recovery. Surgical judgment is of great importance in selecting which patients require left ventricular aneurysm resection.

Simplified subxiphoid placement of implantable cardioverter defibrillators using a posterior rectus pocket.

A simplified subxiphoid procedure using a single longitudinal epigastric incision and posterior rectus pocket for implantable cardioverter defibrillators was used in 100 patients. Through a single incision, ventricular patches are placed via a transverse pericardiotomy, and a pouch is created behind the rectus abdominis muscle in the left upper quadrant for placement of the implantable cardioverter defibrillator. Patients have minimal discomfort soon after operation, and the implantable cardioverter defibrillator generator is imperceptible to most.

Redo cardiac surgery in a patient with severe peripheral vascular disease and pericardial adhesions using subclavian arterial cannulation and port-access technology.

Patients viewed as conventionally inoperative candidates are now given alternative surgical choices. The ability to provide new technology such as the port-access minimally invasive approach, kinetic venous assist, and specialized cannulae have made this possible. This case report discusses the ability to apply and modify this new technology to provide a successful surgical outcome in a patient with severe peripheral vascular disease and dense mediastinal adhesions.

Cost and length of hospital stay: comparisons between nonthoracotomy and epicardial techniques in patients receiving implantable cardioverter defibrillators.

Twenty-five patients with implantable cardioverter defibrillators (ICDs) implanted intrathoracically (group I) were compared with 25 patients who underwent implant using the nonthoracotomy approach (group II). All systems were implanted by the same medical team, in the same high volume implanting center. Indications for implantation were comparable in both groups. Patient characteristics were not statistically different with the exception of age (66-group I vs 71-group II; P < 0.05). Although left ventricular ejection fractions appeared to differ (32% vs 37%, respectively), this difference was not statistically significant (P = 0.06). ICD models used in group I were: Ventritex Cadence (16), Telectronics Guardian 4211 (2), Medtronic PCD (7); in group II they were: Ventritex Cadence (15), Guardian 4211 (2), and CPI 1600 (1). Total length of hospital stay was 16 +/- 6 days for group I versus 12 +/- 5 for group II (P < 0.05). Number of postoperative days in an intensive care unit was 3.2 +/- 2.8 for group I versus 0.5 +/- 0.6 for group II (P < 0.0001). Postoperative length of stay was 8.2 +/- 3.1 for group I versus 5.7 +/- 4.4 for group II (P < 0.001). Mean total hospital charges for the entire length of stay were $72,918 +/- $26,770 in group I versus $55,031 +/- $42,870 in group II, representing a mean reduction of 21% in global costs for group II patients. These data confirm that nonthoracotomy ICD implantation in an experienced center is associated with significantly shorter hospital stays, a virtual elimination of the need for postoperative intensive care, and globally lower total hospital costs. In addition, the presence of a statistically older population in group II does not negate these beneficial effects.

Improved patient surveillance and data acquisition with a third generation implantable cardioverter defibrillator.

Thirteen patients were implanted with the Telectronics 4210 ATP implantable cardioverter defibrillator (ICD) for ventricular tachycardia or ventricular fibrillation. This device has multiprogrammable antitachycardia pacing, bradycardia pacing, and shock therapies. In addition, there is extensive data logging and ECG snapshot capability for arrhythmia confirmation and response to therapy. These features permit easy retrieval of all detected and treated events, whatever the eventual outcome. In this study, the data logged at predischarge electrophysiological testing was compared to the data recorded in a standard manner. The bulk of the data, however, was derived from long-term follow-up of spontaneous events over a mean period of 203 days (range 154-257). During this period, a total of 6,193 arrhythmia detections were made: 20 were classified as ventricular fibrillation, and 6,173 as ventricular tachycardia. The vast majority of these (93%) terminated spontaneously without ICD intervention (5,738), underscoring the benefit of a standard second confirmation prior to therapy delivery (noncommitted system). There were 394 arrhythmia episodes treated with antitachycardia pacing; of these a total of 8.3% accelerated to either more rapid ventricular tachycardia or ventricular fibrillation (4.3% and 4.0%, respectively). Events were reported in an "episode log" format, listing all arrhythmia detections with time/date annotation; or in a "sense history" format, detailing each episode from start to conclusion. These data demonstrate that this advanced, "tiered" ICD with data recall contributes to better patient management, and permits a more tailored termination prescription for the individual patient.

Mechanism of death in patients with the automatic implantable cardioverter defibrillator.

Fifty patients underwent primary implantation of an automatic implantable cardioverter defibrillator between August 1983 and April 1988 and were entered into a long-term surveillance program. There were a total of 14 deaths (28%) in the entire group occurring at a mean of 8.7 months postimplantation. Eleven deaths were cardiac and three were noncardiac (two pneumonia, one leukemia). The group of deceased patients were similar to the survivors in all respects except for a statistically lower ejection fraction (23% vs 32%) at the time of implantation. In addition, 13/14 (93%) of the deceased patients experienced at least one appropriate AICD discharge at a mean of 4.5 months post implantation. Recorded ECGs at the time of death revealed that most of the sudden deaths were due to electromechanical dissociation and not to AICD-treatable arrhythmias. These data suggest therefore that death in AICD patients is usually cardiac, due primarily to low ejection fraction and occurs in patients who have previously received AICD discharges.

Changing trends in therapy delivery with a third generation noncommitted implantable defibrillator: results of a large single center clinical trial.

Thirty-four patients underwent implantation of a third generation ICD, the 4210 ATP, for sudden cardiac death or ventricular tachycardia. This device incorporates significant telemetry logs as well as a detailed analysis of each arrhythmia episode detected. During the period of clinical follow-up, a mean of 12.2 months, a total of 26,569 VT or VF detections were made. The vast majority of these were either due to atrial fibrillation, nonsustained VT, or "noise" detection, and only 6% led to device therapy. ATP was successful in 86.3% of episodes, with 3.5% accelerations and 2.4% failure of ATP trains. The majority of inappropriate therapy episodes were clustered in seven patients, and all were easily diagnosed with the aid of the extensive telemetry logs and sense histories. Of five late deaths, three were from congestive heart failure, one from cerebrovascular accident, and one unknown. These data reveal that this "tiered" therapy noncommitted ICD performs to expectations; the stored data is of significant value in diagnosing the cause of ICD therapy. In addition, ATP is an effective modality for termination of VT.