Awake and aware with ongoing ventricular fibrillation during LVAD treatment: is it possible?

Abstract

Left ventricular assist devices (LVADs) are currently used as destination therapy or bridge to heart transplantation in patients with advanced chronic heart failure (CHF). It has been proved to reduce mortality and symptoms in these patients. Patients with advanced CHF are known to have increased risk of ventricular arrhythmias (ventricular tachycardia or ventricular fibrillation (VF)) despite the presence of LVAD. We report the case of patients with ongoing VF during LVAD treatment while being awake and aware. We discuss the challenges introduced along with the increasing use of LVAD treatment. The decision whether a patient with LVAD automatically should have an implantable cardioverter-defibrillator is challenging. Randomised trials are warranted to shed light on these challenging decisions.

Background

Left ventricular assist devices (LVADs) are currently used as destination therapy (DT) or bridge to heart transplantation in patients with advanced chronic heart failure (CHF). It has been proved to reduce mortality and symptoms in these patients.^{1 2} Patients with advanced CHF are known to have increased risk of ventricular arrhythmias (ventricular tachycardia (VT) or ventricular fibrillation (VF)) despite the presence of LVAD.³

Implantation of implantable cardioverter-defibrillators (ICDs) is still an area of debate in patients with LVAD.⁴ Previously it has been shown that a ‘Fontan-like circulation’ as observed in patients with VF and LVAD is able to maintain adequate haemodynamics without end-organ dysfunction.⁵ In the following, we report a case of a patient with advanced CHF and LVAD who experiences several hours of VF still being awake and aware.

Case presentation

A 72-year-old patient presented to the hospital with severe chest pain and an electrocardiogram (ECG) showing the signs of an anterior ST segment elevation myocardial infarction. An immediate coronary artery angiography was performed and the patient was treated for a proximal left anterior descending artery (LAD) occlusion with percutaneous coronary intervention. During this intervention, the patient developed cardiogenic shock requiring support by extracorporeal membrane oxygenation. This treatment was weaned after 5 days of treatment after increasing the left ventricular ejection fraction to approximately 20%. During the following workup, the patient was also found to have a moderate stenotic aortic valve. After further stabilisation, he was evaluated for subacute treatment with transcatheter aortic valve implantation. This intervention went successful. During the following months, anticongestive treatment was up titrated, however, heart failure symptoms increased significantly with no significant change in left ventricular ejection fraction (15%–20%). Due to the narrow QRS complex, there was no indication for cardiac resynchronisation therapy. Considerations regarding primary preventive ICD implant was performed, however, due deterioration of the patient, evaluation for LVAD was prioritised. A HeartWare (HVAD, HeartWare, Medtronic) with an initial setting with 2600 rounds per minute (rpm) (subsequently increased to 2700 rpm) was inserted uneventfully by a conventional thoracotomy. His postoperative course was satisfactory with carvedilol 30 mg/day, enalapril 2.5 mg/day, aldosterone antagonist 75 mg/day and furosemide 20 mg/day. He was discharged on day 32 and managed in outpatient clinic with New York Heart Association class II symptoms. The following year, the patient was stabilised and fared well.

One and a half year later, the patient contacted the department directly after an episode of dizziness and blackout. Furthermore, the patient reported several ongoing low-flow alarms from the LVAD. The patient was asked to call 9-1-1 emergency and was immediately transported to the department of cardiology. At the time of arrival, the patient was awake, alert, warm and dry. The patient was able to move without any help from the ambulance stretcher to the hospital bed. Blood pressure was measured to 95 mm Hg by Doppler. The ECG performed at arrival showed VF.figure 1 The patient was immediately under sedation converted to sinus rhythm by electrical shock therapy (figure 1). The log file extracted from the LVAD showed multiple low-flow alarms and observed around the time of the 9-1-1 call (figure 2). It also showed multiple suction episodes in the days leading up to the event (figure 3).

Figure 1.

ECG at arrival showing ventricular fibrillation.

Figure 2.

ECG after electrical shock therapy showing sinus rhythm.

Figure 3.

Log file extracted from the left ventricular assist device. Green arrow shows subclinical (no alarms registered) suction from LVAD. Red arrow shows clinical ‘suction alarm’ at the time of ventricular fibrillation start—though with clinical stabilisation despite ongoing ventricular fibrillation. LVAD, left ventricular assist device.

During admission, the patient started amiodarone therapy. It was discussed whether the patient would benefit of an ICD, however, medical treatment with amiodarone was chosen. Furthermore, we reduced the rpm from 2700 to 2500 to avoid further suction episodes and potential interaction by inflow cannula to the epicardium.

Outcome and follow-up

The patient has not experienced any verified incidences of VF or prolonged VT since medical antiarrhythmic treatment was initiated. The patient is still alive and doing well on LVAD treatment.

Discussion

In this case, we report a patient with advanced CHF provided with LVAD awake and aware despite several hours of VF. This patient did not have an ICD implanted due to the abrupt escalation in treatment, resulting in LVAD treatment before ICD decision. It has been reported that the risk of ventricular arrhythmia is increased in LVAD patient due to the risk of the suction events by the inflow cannula and the inherent risk attributed to the heart failure phenotype. The risk of a patient with LVAD to experience shocks from their ICD being awake would be higher and not desirable and with large discomfort for the patient. Although there is sparse evidence for patients on the heart transplant list, ICD implantation is recommended per the current guidelines.^{6 7} No data regarding patients with LVAD treatment for DT exist. Furthermore, no randomised control study investigating the effects of ICDs on mortality in patients with LVAD exists, and conflicting results have been reported.^{4 8} Pros and cons exist as shown in table 1. Several considerations as outlined in table 1 must be kept in mind during the decision process.

Table 1.

Pros and cons for ICD implantation in LVAD patients

Pros	Cons
Therapy with antitachycardia pacing during VT	Shock therapy while patient is awake
Psychological safety	Psychological distress
Decreasing risk of complicating right ventricular failure during persistent VT/VF	Risk of infection
	Electrical interference with LVAD causing inappropriate shock therapy

ICD, implantable cardioverter-defibrillator; LVAD, left ventricular assist device; VF, ventricular fibrillation; VT, ventricular tachycardia.

In the present case, an activated ICD would have delivered shock therapy while the patient was still awake. As illustrated in this case, it can be challenging to decide whether a patient with LVAD and ventricular arrhythmias should be provided with an ICD or not. Currently, it is not known whether long-term damages of prolonged VF will develop, but it seems unlikely that a sufficient perfusion of the organs can be sustained for extended time. A patient with VF longer than 12 hours has been described though, where there were found no signs of organ hypoperfusion and dysfunction. In general, a randomised controlled trial to show the efficacy of routine ICD implantation in LVAD is warranted.

Recurrent ventricular arrhythmia despite optimal antiarrhythmic treatment is challenging. Ventricular substrate ablation is a well-known option that has been described effectively.⁹ Further elaboration regarding the role of ablation therapy versus device therapy in the clinical situation is desirable.

Learning points.

• Appropriate attention must be shown when patients with leftventricular assist device (LVAD) have clinical complaints and low-flow alarms.

• Considerations regarding the implantablecardioverter-defibrillator (ICD) implant in patients with LVAD have to be discussed in depth when planning LVAD in patients without ICDs.

• Patients have to be included in the decision-making process whether to implant ICD when an LVAD treatment is considered.