Intractable ventricular tachycardia and bridging to heart transplantation with a non-pulsatile flow assist device in a patient with isolated left-ventricular non-compaction

Neuroversion: using electroconvulsive therapy as a bridge to deep brain stimulation implantation

Parkinson's disease (PD) is a movement disorder with significant neuropsychiatric comorbidities. Electroconvulsive therapy (ECT) is effective in treating these neuropsychiatric symptoms; however, clinicians are reluctant to use ECT in patients with deep brain stimulation (DBS) implantations for fear of damaging the device, as well as potential cognitive side effects. Right unilateral ultra-brief pulse (RUL UBP) ECT has a more favorable cognitive side-effect profile yet has never been reported in PD patients with DBS implants. We present a case series of three patients with a history of PD that all presented with psychiatric decompensation immediately prior to planned DBS surgery. All three patients had DBS electrode(s) in place at the time and an acute course of ECT was utilized in a novel method to "bridge" these individuals to neurosurgery. The patients all experienced symptom resolution (psychosis and/or depression and/or anxiety) without apparent cognitive side effects. This case series not only illustrates that right unilateral ultra-brief pulse can be utilized in patients with DBS electrodes but also illustrates that this intervention can be utilized as a neuromodulatory "bridge", where nonoperative surgical candidates with unstable psychiatric symptoms can be converted to operative candidates in a manner similar to electrical cardioversion.

Left ventricular non-compaction cardiomyopathy and left ventricular assist device: a word of caution

Background

In patients with left ventricular non-compaction (LVNC), implantation of a left ventricular assist device (LVAD) may be performed as a bridge to transplantation. In this respect, the particular characteristics of the left ventricular myocardium may represent a challenge.

Case presentation

We report a patient with LVNC who required urgent heart transplantation for inflow cannula obstruction nine months after receiving a LVAD. LVAD parameters, echocardiography and examination of the explanted heart suggested changes of left ventricular configuration brought about by LVAD support as the most likely cause of inflow cannula obstruction.

Conclusions

We conclude that changes experienced by non-compacted myocardium during LVAD support may give rise to inflow cannula obstruction and flow reduction. Presence of LVNC mandates tight surveillance for changes in LV configuration and LVAD flow characteristics and may justify urgent transplantation listing status.

First series of mechanical circulatory support in non-compaction cardiomyopathy: Is LVAD implantation a safe alternative?

BACKGROUND

Left ventricular non-compaction (LVNC) is a rare cardiac disorder characterized by prominent trabeculae and deep recesses of the ventricular myocardium. Patients with LVNC may develop severe congestive heart failure refractory to medical therapy. However, heart transplantation is strongly limited due to donor organ shortage. Thus mechanical circulatory support by left ventricular assist devices (LVADs) is a promising alternative. Nevertheless, hypertrabeculation and proarrhythmogenic potential in LVNC might represent important hurdles for success of LVAD therapy in these patients.

METHODS AND RESULTS

We retrospectively analyzed the data of a total of 5 patients (3 HVAD, Heartware®; 2 HeartMate II, Thoratec®) with LVNC who underwent LVAD implantation in our institution between 2010 and 2014. Mean follow-up time was 86.5weeks. 30-day survival was 100% without major intrahospital complications. During follow-up, 3 patients developed pump thrombosis requiring pump replacement. Arrhythmias were not detected during follow-up as assessed by ICD interrogation.

CONCLUSIONS

LVAD implantation in LVNC can be performed with low intrahospital complication rates. However, we observed a high incidence of pump thrombosis during follow-up, possibly related to thromboembolic predisposition by the underlying LVNC. Therefore, careful management of anticoagulation appears to be critical in these patients.

Reverse electrophysiologic remodeling after cardiac mechanical unloading for end-stage nonischemic cardiomyopathy

BACKGROUND

Left ventricular assist devices (LVAD)-induced unloading appear to cause reverse cardiac remodeling. However, its effect on arrhythmogenicity is a controversial issue, and prospective data are lacking. We sought to investigate the impact of LVAD-induced unloading on the electrical properties of the failing heart.

METHODS

We prospectively studied the effects of LVAD therapy on QRS, QT, and QTc durations and ventricular arrhythmias from electrocardiograms and 24-hour ambulatory electrocardiograms recorded before and during 6 months of mechanical support in 12 LVAD patients and 7 other patients with advanced nonischemic cardiomyopathy untreated with LVAD.

RESULTS

After 1 week of LVAD support, QTc duration had decreased from 479 ± 79 ms to 411 ± 57 ms (p = 0.037), and QRS duration from 150 ± 46 ms to 134 ± 32 ms (p = 0.029). At 6 months, QTc was found to be 372 ± 56 ms (p = 0.046 versus baseline, 15% shortening) and QRS 118 ± 25 ms (p = 0.028 versus baseline, 11% shortening). A strong correlation was found between QTc shortening and increase in left ventricular ejection fraction and decrease in left ventricular filling pressures. After 2 months of LVAD support, premature ventricular contractions had decreased from 3,507 ± 4,252 to 483 ± 417 in 24 hours (p = 0.043), ventricular couplets from 82 ± 99 to 29 ± 25 in 24 hours (p = 0.05), and ventricular runs from 9 ± 8 to 10 ± 9 (not significant). No patient died suddenly or suffered a symptomatic arrhythmic event during follow-up. No significant electrocardiographic, functional, or hemodynamic change was observed in the 7 patients untreated with LVAD.

CONCLUSIONS

The LVAD support caused progressive shortening of QTc and QRS intervals, consistent with reverse remodeling of the failing heart's electrical properties, accompanied by a decrease in frequency of ventricular arrhythmias.

Failure of transvenous ICD to terminate ventricular fibrillation in a patient with left ventricular noncompaction and polycystic kidneys

Implantable cardioverter defibrillator (ICD) testing in patients with left ventricular noncompaction (LVNC) at the time of implantation and potential difficulties with ventricular fibrillation (VF) induction/termination in LVNC patients are often not stated in the literature. This report describes the failure of transvenous implantation of an ICD in a 40-year-old patient with LVNC and polycystic kidneys. A high defibrillation threshold (DFT) prevented termination of ICD-induced VF. This case suggests that DFT testing should be considered in any LVNC patient during ICD implantation. The association of LVNC and polycystic kidneys is also discussed.

Mechanical circulatory support in the ICCU

The mortality of acute heart failure (AHF) remains high despite advances in treatment. Mechanical circulatory support (MCS) can be applied in AHF, refractory to conventional measures, to improve outcomes. This article aims to describe the current and the prospective role of MCS in the treatment of AHF. The support strategies and the indications of MCS are continuously evolving, including situations considered as contraindications in the past. Appropriate patient selection, advanced device technology and improved patient management have contributed to the substantially improved results. Evolution in device technology results in evolution of the clinical applications of MCS. Earlier application of MCS, with novel, flexible and individualized support strategies is now feasible. Bridging to recovery is the most intriguing support strategy and bridging to future treatments is feasible with long-term support. The progressively expanding role of MCS in the treatment of heart failure is not reflected in the existing guidelines. Being reserved for refractory heart failure, MCS has been applied to the sickest patients who were less amenable to randomization. This explains the lack of robust evidence, but also highlights the value of the progressively improving results. The anticipated wider application of MCS should be better defined, systematically recorded, and guided.

Left ventricular noncompaction

According to the World Health Organization classification of cardiomyopathies, left ventricular noncompaction is still an unclassified cardiomyopathy. In 2006, the American Heart Association classified this entity as a primary cardiomyopathy of genetic origin. In 2008, the European Society of Cardiology updated the classification scheme similar to the World Health Organization classification. At present, there is no consensus on the diagnostic criteria, and diagnosis is based on the morphologic features identified by cardiac imaging studies or at autopsy. Due to lack of standardization of the diagnostic criteria and little awareness of this condition among clinicians, the true prevalence of this disease is not clear. There is no specific therapy for this condition. However, it seems prognosis is much better than initially reported. The current status of diagnosis, prognosis, and management of isolated noncompaction in adults is discussed in this review.

Cytoskeletal basis of ion channel function in cardiac muscle

The heart is a force-generating organ that responds to self-generated electrical stimuli from specialized cardiomyocytes. This function is modulated by sympathetic and parasympathetic activity. In order to contract and accommodate the repetitive morphological changes induced by the cardiac cycle, cardiomyocytes depend on their highly evolved and specialized cytoskeletal apparatus. Defects in components of the cytoskeleton affect the ability of the cell to compensate at both functional and structural levels in the long term. In addition to structural remodeling, the myocardium becomes increasingly susceptible to altered electrical activity, leading to arrhythmogenesis. The development of arrhythmias secondary to structural remodeling defects has been noted, although the detailed molecular mechanisms are still elusive. Here, the author reviews the current knowledge of the molecular and functional relationships between the cytoskeleton and ion channels, and discusses the future impact of new data on molecular cardiology research and clinical practice.

Endocardial catheter ablation of ventricular tachycardia in patients with ventricular assist devices

BACKGROUND

The outcomes of patients with ventricular assist devices (VADs) who undergo catheter ablation for ventricular tachycardia (VT) have not been reported.

OBJECTIVE

The purpose of this study was to assess the feasibility, safety, and efficacy of endocardial VT ablation in patients with VADs.

METHODS

We retrospectively reviewed three cases at our institution where endocardial catheter ablation was performed in patients with VADs and incessant VT.

RESULTS

Three patients with underlying cardiomyopathies and VADs underwent VT ablation for incessant VT refractory to multiple antiarrhythmic medications. In each case, VT was either eliminated or significantly ameliorated by catheter ablation. No procedure-related complications occurred. The hemodynamic stability afforded by the VAD played an important role in facilitating ablation in two of the cases.

CONCLUSION

Catheter ablation for VT in VAD patients appears to be feasible, safe, and effective based on our initial experience. Several technical issues, such as decreases in ventricular volumes that can limit maneuverability of the ablation catheter and potential entrapment of the mapping catheter in the inflow cannula, need to be considered at the time of ablation.

Neuromuscular implications in left ventricular hypertrabeculation/noncompaction

This review focuses on recent advances in the association between left ventricular hypertrabeculation/noncompaction (LVHT), a form of unclassified cardiomyopathy, and neuromuscular disorders (NMD). So far, LVHT has been found in single patients with dystrophinopathy, dystrobrevinopathy, laminopathy, zaspopathy, myotonic dystrophy, infantile glycogenosis type II (Pompe's disease), myoadenylate-deaminase deficiency, mitochondriopathy, Barth syndrome, Friedreich ataxia, and Charcot-Marie-Tooth disease. Most frequently LVHT is found in patients with Barth syndrome and mitochondrial disorders. The prevalence of LVHT in NMD patients is not known. On the contrary, NMD can be detected in up to four fifths of the patients with LVHT. Because LVHT is associated with an increased risk of rhythm abnormalities and heart failure, it is essential to detect LVHT as soon as possible. Because of adequate therapeutic options, all patients with NMD should undergo a comprehensive cardiological examination as soon as their neurological diagnosis is established. In reverse, all patients with LVHT should undergo a comprehensive neurological investigation following the detection of LVHT.

Peripheral Vascular Reactivity in Patients With Pulsatile vs Axial Flow Left Ventricular Assist Device Support

BACKGROUND

Left ventricular assist devices (LVADs) are either pulsatile or axial flow devices. The latter can be operated at a low-speed setting to allow pulsatility or at a high-speed setting to create continuous flow. The purpose of this study was to compare the effect of continuous flow and pulsatile flow on peripheral vascular reactivity.

METHODS

Twenty consecutive patients were divided into two groups based on the type of LVAD they received. Ten patients had a pulsatile flow LVAD, and 10 had an axial flow LVAD. For the purpose of the study protocol, the axial flow devices were operated at a high speed to ensure continuous flow. The patients' peripheral artery vasoreactivity was assessed with an ultrasound vascular transducer that measured flow-mediated dilation (FMD).

RESULTS

The FMD of the patients supported with pulsatile flow (15.6 +/- 5%) was higher than the FMD of the patients supported with temporary continuous flow (1.8 +/- 3%). The difference was statistically significant (p < 0.0001).

CONCLUSIONS

Pulsatile flow is associated with a better peripheral vascular reactivity than continuous flow. Patients supported by axial flow devices should be kept on the lowest speed setting to allow maximum pulsatility.