Right and left ventricular interaction in ventricular fibrillation with mechanical maintenance of the circulation.

OBJECTIVE: To investigate the possible mechanisms of right and left ventricular interaction during ventricular fibrillation (VF) with mechanical maintenance of the circulation. EXPERIMENTAL DESIGN: In this experimental study, two para-aortic counterpulsation devices (PACDs) were implanted in 14 mongrel dogs. SETTING: The PACD is a spheroid, valveless, with one opening, 100 ml stroke volume assisting device. After midsternotomy and pericardiotomy, two PACDs were implanted on the ascending aorta and the pulmonary artery, respectively. Catheters were placed into the aortic arch, and the left and right ventricles. An electromagnetic probe was placed on the descending aorta. INTERVENTIONS: After the completion of the experimental preparation, VF was induced and the two devices were synchronized and pumped simultaneously for 10 minutes (A). Subsequently, the left sided PACD pumped alone for the same period of time (B). This sequence was repeated 1-10 times in each experiment. MEASURES: The aortic pressures, the left and right ventricular pressures and the cardiac index were obtained at the end of each intervention. RESULTS: The simultaneous pumping of the two devices (A) compared with the pumping of that implanted on the ascending aorta (B) resulted in: higher peak aortic pressure 119.1+/-32.1 mmHg (A) vs 105.7+/-36.4 mmHg (B), p<0.001, mean aortic pressure 42.1+/-13.2 mmHg vs 27.8+/-10.5 mmHg, p<0.001, mean left ventricular pressure 18.4+4.0 mmHg vs 11.7+/-3.6 mmHg, p<0.001, and cardiac index 105.7+/-40.1 ml/kg/min vs 82.0+/-39.9 ml/kg/mm, p<0.001, and lower right ventricular pressure 10.1+/-3.2 mmHg vs 13.3+/-2.6 mmHg, p<0.001. CONCLUSIONS: Maintenance of the circulation during VF with the PACD implanted on the ascending aorta results in equalization of the right and left ventricular pressures. In contrast, when both devices are pumping simultaneously, the left ventricular pressure is significantly higher than the right one and the assistance is more effective.

Adjuvant chemotherapy with dacarbazine, vindesine, and cisplatin in pathological stage II malignant melanoma.

Following curative lymph node dissection, 28 patients with pathological Stage II malignant melanoma (metastatic to regional lymph nodes) received adjuvant chemotherapy with dacarbazine, vindesine, and cisplatin (DVP); 32 more patients with similar characteristics refused adjuvant treatment. In the treated group, 15 patients (53%) developed dissemination of disease after 4 to 29 months; 20 (62%) of the patients who refused adjuvant treatment recurred after 4 to 25 months and received palliative treatment with DVP. No significant differences in survival or disease-free survival according to different patient characteristics could be detected between these two groups with the available patient population. Large and well-designed prospective randomized trials are required to determine if the adjuvant use of this treatment schedule, which includes the three most active drugs improves survival in patients with nondisseminated melanoma.

Cisplatin-containing regimen in advanced or recurrent granulosa cell tumours of the ovary.

The efficacy of combination chemotherapy in advanced or recurrent disease of granulosa cell tumours is still not well defined. Ten patients with advanced or recurrent granulosa cell tumours were treated with cisplatin, adriamycin and cyclophosphamide (CAP). Prior to chemotherapy all patients underwent surgical treatment. No patient received prior hormonochemotherapy or radiotherapy. Five complete responses (three pathologically documented) and one partial response were obtained for a total response rate of 60%. One pathologically-complete responder relapsed after 48 months from the onset of chemotherapy, but responded completely to debulking surgery and radiotherapy and remains well with no evidence of disease 87+ months. Five patients are still alive with no evidence of disease at 10+, 26+, 41+, 46+, 87+ months, 1 is still alive with disease and 4 have died at 20, 22, 28 and 60 months despite further treatment. Additional cooperative clinical trials are required to determine the exact efficacy of cisplatin chemotherapy in granulosa cell tumours.

Maintenance of circulation during ventricular fibrillation with the simultaneous use of two "counterpulsation" devices.

Two valveless, single orifice counterpulsation devices, with pumping stroke volumes of 65 ml each, were implanted on the ascending aorta and pulmonary artery of seven open chest anesthetized dogs. After completion of the preparation, ventricular fibrillation was induced. The devices were synchronized to pump simultaneously at a rate of 85-100 bpm. The combined use of the counterpulsation devices provided maximal aortic pressure of 111.4 +/- 25.1 mmHg during ventricular fibrillation for a period of 15-60 min. The mean left ventricular pressure was 17.7 +/- 4.4 mmHg, and the cardiac index 64.5 +/- 23.6 ml/kg/min. Cardioversion of ventricular fibrillation to sinus rhythm restored normal hemodynamics. The counterpulsation device implanted on the ascending aorta was not able to maintain circulation for more than 5 min after the induction of ventricular fibrillation, if used alone. In conclusion, the use of two counterpulsation devices implanted on the ascending aorta and pulmonary artery was able to maintain circulation in experimental animals during ventricular fibrillation.

Additional salutary hemodynamic effects of the combined use of the paraaortic counterpulsation device and intraaortic balloon pump versus a paraaortic counterpulsation device alone.

The hemodynamic effects of the combined use of the paraaortic counterpulsation device (PACD) (stroke volume 65 ml) implanted on the ascending aorta, and a 20 ml intraaortic balloon pump (IABP) placed in the descending aorta, were compared with the PACD working alone in 12 dogs after the induction of heart failure. Heart failure was characterized by left ventricular end-diastolic pressure (LVEDP) greater than 18 mmHg and systolic aortic pressure (SAP) in stage A: 116 mmHg greater than or equal to SAP greater than 70 mmHg; in stage B: 70 mmHg greater than or equal to SAP greater than 30 mmHg; and in stage C: SAP less than or equal to 30 mmHg. Both modalities of mechanical assistance produced significant salutary hemodynamic effects in stages A and B. No difference was observed in stage C. In conclusion, the combined use of PACD and IABP is more effective than the use of either of these devices alone. This modality of mechanical assistance may easily be applied in patients that cannot be weaned from extracorporeal circulation, and in whom IABP was unsuccessfully applied.

Treatment of metastatic malignant melanoma with dacarbazine, vindesine and cisplatin.

Twenty-seven patients with disseminated malignant melanoma were treated monthly with cisplatin (CDDP) 120 mg m-2 on day 1, vindesine (VDS) 3 mg m-2 on day 2 and dacarbazine (DTIC) 250 mg m-2 on days 2-6. None of them had received prior chemotherapy. All patients are evaluable for response and toxicity. There were five (19%) complete (CR) and seven (26%) partial (PR) responses for a total response rate of 45%. We conclude that the combination of DTIC, VDS and CDDP is capable of producing a relatively high rate of response in patients with advanced metastatic malignant melanoma, but responses are short.