Hypothermia for the treatment of postsurgical greatly accelerated junctional ectopic tachycardia.

Three infants developed greatly accelerated junctional ectopic tachycardia with a heart rate greater than 200 beats/min after open heart surgery. When the heart rate exceeded 200 beats/min for 5 hours, all the infants had congestive heart failure and clinical signs of low cardiac output. Conventional therapy (cardioversion, lidocaine, verapamil, digoxin and ice to face) has been shown in the past to be unsuccessful in controlling the heart rate. Because hypothermia is known to decrease automaticity of the heart, these patients were treated with induced hypothermia. The goal was to arbitrarily decrease the junctional ectopic rate to less than 180 beats/min to increase cardiac filling time. The duration of the junctional ectopic tachycardia greater than 180 beats/min ranged from 0.5 to 17 hours after cooling began. The duration of the hypothermia ranged from 4 to 24 hours. Spontaneous reversion to sinus rhythm occurred either during the hypothermia or shortly thereafter in all three patients. The blood pressure and urinary output remained stable during hypothermia. Hypothermia is an effective means of controlling the rate of greatly accelerated junctional ectopic tachycardia after open heart surgery in infants. Although hypothermia does not convert junctional ectopic tachycardia to sinus rhythm, it slows the rate to a more acceptable level, allowing the infants' survival and eventual recovery of sinus rhythm.

Experience with aortic and mitral valve replacement in children.

Ninety-two children underwent aortic (AVR) or mitral valve replacement (MVR), or both, at the Hospital for Sick Children in Toronto from 1963 to February, 1980. No early or late deaths occurred in 39 children having AVR. However, in 50 children having MVR, the operative mortality was 32% and the actuarial survival rate 5 years after operation was only 50%. Major complications occurred with almost equal frequency in the two groups; 50% of children surviving AVR or MVR experienced major complications within 6 years of operation. Retrospective comparison of results with tissue and mechanical valves showed no clear advantage with either type of prosthesis. Outgrowth of a prosthetic valve was satisfactorily managed in children with AVR but presented a difficult problem in those with MVR, who required frequent reoperation to increase the prosthetic valve to adult size. Prosthetic valve replacement in children is a palliative procedure at best, and every effort should be made to preserve the natural valve by a more conservative repair technique.

Intracranial bleed during bridge to transplant may not preclude a successful result.

We report the case of a 29-year-old man who suffered sub-arachnoid bleeding while stabilized on a biventricular assist device as a bridge to cardiac transplantation. We adjusted his anti-coagulation therapy to control the bleeding and to concurrently minimize thrombosis while on support. He underwent 2 craniotomy operations to evacuate sub-arachnoid hematomas, and he underwent a subsequent operation to debride and close the dura. Eighteen days later, he underwent successful orthotopic heart transplant and was discharged to home 3 weeks post-transplant.

Reversibility of hepatic failure following jejunoileal bypass.

Jejunoileal bypass was performed in 50 morbidly obeses patients. The morbidity encountered compared favorably with that of other series. All patients manifesting hepatic failure demonstrated hyperbilirubinemia within the first three months postoperatively. Hyperbilirubinemia, if uncorrected, resulted in a mortality of 75%. Augmentation jejunal interposition was performed in three patients who demonstrated hepatic decompensation or severe electrolyte imbalance or both. This resulted in rapid correction of electrolyte disturbances, liver function measurements, and patient symptoms without significant postoperative weight gain. Persistent hyperbilirubinemia or recalcitrant electrolyte problems or both are indications for augmentation jejunal interposition.

Staged repair of acute type I aortic dissection and coarctation in pregnancy.

A 29-year-old gravid female presented at 22 weeks gestation with an acute Type I aortic dissection and coarctation of the aorta. She underwent emergent repair of her aortic dissection using cardiopulmonary bypass and hypothermia. At 25 weeks gestation, she underwent repair of her coarctation of the aorta. The patient had a cesarean delivery of a viable, normal male infant at 39 weeks gestation.

Noncoronary collateral distribution in coronary artery disease.

Noncoronary collateral flow is a potential hazard when cold cardioplegia is used for myocardial protection. In this study, noncoronary collateral flow was observed during coronary revascularization in 58 patients. It was distributed significantly (p less than 0.005) toward arteries demonstrating intercoronary collateral flow angiographically - 1.0 of 35 with and 12 of 121 without. Preponderance of coronary collateral flow in hearts with more extensive disease may complicate cardioplegic myocardial protection for such patients.

Use of the "chimney patch" technique for Norwood stage I procedures.

The Norwood stage I procedure is often used for the initial treatment of infants with hypoplastic left heart syndrome. This procedure creates a systemic arterial to pulmonary artery shunt to establish pulmonary blood flow. We describe a method to facilitate placement of this shunt by attaching a polytetrafluoroethylene shunt to a pulmonary artery homograft patch before performing the median sternotomy. This technique facilitates the performance of the proximal shunt anastomosis and expedites the procedure.

Bridge to recovery for postcardiotomy failure: is there still a role for centrifugal pumps?

BACKGROUND: Early implantation of centrifugal devices in patients with postcardiotomy cardiogenic shock may provide a bridge to recovery and allow subsequent long-term survival. METHODS: Since January 1989, 62 patients were supported with centrifugal pumps because of failure to wean from cardiopulmonary bypass. Indications were postcardiotomy cardiogenic shock (PCCS) (n = 60), bridge to cardiac retransplantation (n = 1), and right ventricular failure (n = 1). Patients' ages ranged from 23 to 78 years; 40 were men (65%), and 22 were women (35%). Twenty-two patients (35%) had a left ventricular assist device; 9 patients (15%) had a right ventricular assist device; and 31 patients (50%) had a biventricular assist device. Length of support ranged from 1 day to 19 days. RESULTS: Forty-two patients (68%) were weaned successfully; 27 patients survived to discharge (44%). Complications included bleeding (n = 41, 66%), renal failure (n = 28, 45%), and respiratory failure (n = 26, 42%). Currently, 23 patients survived 10 or more years (n = 1), 6 to 10 years (n = 7), 1 to 5 years (n = 10), and less than 1 year (n = 5). CONCLUSIONS: Centrifugal pumps are available, easy to use, and relatively inexpensive. Our experience justifies their continued use as a bridge to recovery for patients with postcardiotomy cardiogenic shock, despite the availability and increasing use of more expensive devices.

Homograft replacement of mitral valve in children.

BACKGROUND: Recent reports have demonstrated successful early outcomes using mitral valve homografts in adults. We report our early results after homograft mitral valve replacement in 4 children with previous atrioventricular septal defects, previous placement of a prosthetic valve, and rheumatic valvular disease. METHODS: Between May 1996 and June 1997, 4 children (ages 5, 11, 13, and 15 years) underwent mitral valve replacement with cryopreserved mitral valve homografts at our institution. Preoperative echocardiography confirmed moderately severe to severe mitral regurgitation, stenosis, or both in all 4 patients. RESULTS: Successful homograft valve replacement was achieved in all 4 patients. Based on symptoms, physical examinations, and echocardiographic follow-up, all four homograft mitral valves are functioning well with normal hemodynamics. None of these patients are receiving warfarin. Follow-up has been limited to 10 months. CONCLUSIONS: In children requiring mitral valve replacement, the use of mitral valve homografts offers advantages over prosthetic valves, such as the avoidance of complications associated with thrombosis and anticoagulation. Homograft mitral valve replacement is technically feasible in children with congenital and rheumatic heart disease and previous prosthetic valves.

A 10-year experience with postpump chorea.

Postpump chorea (PPC) is the development of choreoathetoid movements within 2 weeks following cardiopulmonary bypass. Over a 10-year period, 668 children underwent open cardiac surgery, of whom 8 (1.2%) developed PPC. Age at surgery ranged from 8 to 34 months. The onset of chorea was 3 to 12 days following surgery. Computed tomography and magnetic resonance imaging showed atrophy but no focal lesions. Cerebral positron emission tomography using [18F]fluorodeoxyglucose in a patient following 12 months of chorea showed patchy areas of decreased glucose metabolism. None of the patients were developmentally normal 22 to 130 months following surgery. Three patients have had transient and 5 have persistent chorea. Neurological deficits ranged from a mild learning disability to progressive hypotonia and obtundation ending in death. One of 4 patients who received haloperidol had a decrease in the severity of chorea. We compared PPC patients with 39 randomly selected controls. During surgery, affected patients spent significantly more time on pump and at temperatures under 36 degrees C, were cooled to lower temperatures than controls, and were more likely to have had a circulatory arrest. One patient developed chorea without a history of circulatory arrest. We conclude that (1) there is a strong association between PPC, deep hypothermia, and circulatory arrest, (2) absence of characteristic macroscopic changes suggests a biochemical or microembolic etiology in some cases, (3) chorea is frequently associated with developmental delay, and (4) the prognosis for complete resolution of chorea is guarded.

Prolonged ventricular support using a centrifugal pump.

The Biomedicus centrifugal pump was required to provide prolonged ventricular support to 13 patients with hemodynamic instability: 11 after cardiovascular surgical procedures, 1 after myocardial infarction and 1 after failure of a heart transplant. The duration of support ranged from 3.5 hours to 9 days (mean 72 hours). Complications included bleeding in six patients, renal insufficiency in three and central nervous system deficit in three. Six patients (46%) were successfully weaned from the pump. The patient with graft failure had hyperacute rejection of a second heart. Five patients were discharged from the hospital. There was one death 8 months postoperatively. Prolonged ventricular support with the centrifugal pump may allow recovery of potentially reversible ventricular dysfunction in selected patients after cardiac surgical procedures.