Successful treatment of life-threatening ventricular tachycardia with high-dose propranolol under extracorporeal life support and intraaortic balloon pumping

Extracorporeal life support for refractory ventricular tachycardia

Extracorporeal life support (ECLS) is a very effective bridging therapy in patients with refractory ventricular tachycardia (VT) associated with cardiogenic shock. A moribund patient in extremis, is not amenable to optimization by standard ACC/AHA guidelines. New approaches and novel salvage techniques are necessary to improve outcomes in patients with refractory clinical settings such as malignant ventricular arrhythmias, cardiac arrest, cardiogenic shock and/or pulmonary failure until further management options are explored. Data base searches were done using key words such as ECLS, VT, cardiac arrest, VT ablation, venoarterial extra-corporeal membrane oxygenation (VA-ECMO). The use of ECLS has been described in a few case reports to facilitate VT ablation for incessant VT refractory to medical therapy. For patients with, out-of- hospital ventricular fibrillation (VF) and VT, Minnesota Resuscitation Consortium has implemented emergent advanced perfusion and reperfusion strategy, followed by coronary angiography and primary coronary intervention to improve outcome. The major indications for ECLS are cardiogenic shock related to acute myocardial infarction, myocarditis, post embolic acute cor pulmonale, drug intoxication and post cardiac arrest syndrome with the threat of multi-organ failure. ECLS permits the use of negative inotropic antiarrhythmic drug therapy, facilitates the weaning of catecholamine administration, thereby ending the vicious cycle of catecholamine driven electric storm. ECLS provides hemodynamic support during ablation procedure, while mapping and induction of VT is undertaken. ECLS provides early access to cardiac catheterization laboratory in patients with cardiac arrest due to shockable rhythm. The current evidence from literature, supports the use of ECLS to ensure adequate vital organ perfusion in patients with refractory VT. ECLS is a safe, feasible and effective therapeutic option when conventional therapies are insufficient to support cardiopulmonary function. A highly driven multidisciplinary team approach is essential to accomplish this task.

Efficacy of veno-arterial extracorporeal membrane oxygenation in acute myocardial infarction with cardiogenic shock

AIM

We analyzed the results of acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) necessitating extracorporeal membrane oxygenation (ECMO), and investigated for the associated risk factors for poor clinical outcomes.

METHODS

We retrospectively reviewed the medical records of 27 patients who required ECMO for AMI associated with CS between April 2006 and July 2010. Mean age was 63.7 ± 11.0 (range: 45-81) years, and there were 16 males (59.3%).

RESULTS

The mean duration of ECMO support was 30.2 ± 30.1 (range: 1-141)h. Cardiopulmonary resuscitations (CPR) were performed in 21 patients (77.8%) before ECMO initiation. Twenty-two patients (81.5%) were successfully weaned off ECMO, and 16 patients (59.3%) survived to discharge. The 30-day mortality was 37.0% (10/27 patients). Complications developed in 17 patients (63.0%: pneumonia in 10 patients, acute renal failure in 10 patients, massive bleeding in 4 patients, and thromboembolic event in 1 patient). The period between CPR initiation and ECMO commencement was a significant risk factor for ECMO weaning failure. High pre-ECMO serum lactate level was identified as a significant risk factor for poor survival on univariated and multivariated analysis.

CONCLUSION

ECMO support could improve survival in patients who suffer AMI associated with CS, and early ECMO initiation yields better outcomes (successful ECMO weaning).

The determinant of severe cerebral dysfunction in patients undergoing emergency extracorporeal life support following cardiopulmonary resuscitation

We investigated the factors associated with cerebral dysfunction in patients undergoing extracorporeal life support (ECLS) following conventional advanced cardiac life support (ACLS). The subjects were 9 patients in whom ECLS was started following ACLS because of intractable cardiac arrest. We investigated whether the irreversibility of cerebral dysfunction during ECLS was related to the cardiopulmonary resuscitation (CPR) time, arterial pH and blood gases, hemoglobin concentration (Hb), peak arterial pressure (PAP) before the start of ECLS and total doses of epinephrine and sodium bicarbonate administered during CPR. Two of the 3 patients who recovered consciousness were weaned from ECLS and survived, while all 6 patients who did not recover from coma were not weaned and died. There was no difference in the CPR time, Hb and PAP before the start of ECLS along with total doses of epinephrine and sodium bicarbonate administered during CPR between the patients who recovered consciousness and those who did not. In addition, there was no difference in arterial pH and blood gases except the arterial oxygen tension (PaO2) between the groups. The PaO2 values before the start of ECLS in the patients who remained in coma ranged from 34 to 58 mmHg, whereas those in the patients who recovered consciousness ranged from 132 to 442 mmHg. The PaO2 values before the start of ECLS in the patients who remained in coma were less than 60 mmHg, whereas those in the patients who recovered consciousness were over 60 mmHg. The present study suggests that hypoxemia during CPR may play a major role in severe cerebral dysfunction in patients undergoing ECLS and PaO2 during CPR.

Emergency and long-term extracorporeal life support following acute myocardial infarction: rescue from severe cardiogenic shock related to stunned myocardium

There has been no report regarding therapy of extracorporeal life support (ECLS) that showed stunned myocardium echocardiographically and electrocardiographically in patients with acute myocardial infarction. ECLS was performed in eight patients with cardiogenic shock or arrest unresponsive to catecholamines and intra-aortic balloon pumping following myocardial infarction; these patients required prolonged external cardiac massage. After the initiation of ECLS, both blood pressure and metabolic acidosis improved in all patients. Four of eight patients were weaned from ECLS after a mean of 69.3 h, which was far longer than previously reported in patients with ischemic heart disease. Three of these patients survived, and cardiac function recovered to NYHA class II in two of the survivors and class III in the other. The other five patients did not recover from coma during ECLS and died. A marked improvement of ventricular wall motion was seen in two survivors with the disappearance of pathologic Q waves after the initiation of ECLS. No occlusion of the coronary arteries or bypass grafts was observed in any of the survivors. These findings suggested the existence of stunned myocardium with myocardial reperfusion. The recovery of stunned myocardium may be delayed for days or even weeks, hence the extended period of ECLS therapy was theoretically justifiable. We conclude that long-term ECLS is a useful therapeutic method for patients with severe cardiogenic shock that is related to stunned myocardium.