Near‐Fatal ICD Lead Dysfunction with Implications for ICD Testing

A 31‐year‐old male patient with an implantable cardioverter defibrillator (ICD) experienced ventricular fibrillation. After resuscitation, no communication between the device and an ICD programmer was possible. The ICD was explanted, no signs of destruction were visible, and the ICD leads revealed normal values. A new ICD was implanted, interrogation values were stable. However, immediately after defibrillation testing the connection between programmer and ICD was interrupted and could not be established again. The device showed burn marks and a hole in the can. Analysis revealed an isolation defect of the ICD lead, which was not detectable with standard interrogation.     

A case of electromagnetic interference between HeartMate 3 LVAD and implantable cardioverter defibrillator

Implantable cardioverter defibrillators (ICDs) have been shown to have a significant benefit in reducing sudden cardiac death (SCD) in patients with systolic heart failure. Additionally, cardiac devices as a bridge to transplant or destination therapy are often used in patients with end‐stage systolic heart failure. As a result, most patients with left ventricular assist devices (LVADs) also have an ICD. Here, we present an electromagnetic interference (EMI) between HeartMate 3 LVAD and ICD. This issue might be critical for both electrophysiologists and advanced heart failure cardiologists to understand prior to implantation of ICD/LVADs in these patients.     

A Rare type of Ventricular Oversensing in ICD Therapy—Inappropriate ICD Shock Delivery Due to Triple Counting

Irregular sensing by triple counting of wide QRS complexes resulted in inappropriate shocks in a patient with a biventricular implantable cardioverter defibrillator (ICD): A 66‐year‐old male patient with ischemic cardiomyopathy, left bundle branch block, and impaired left ventricular function received a biventricular ICD for optimal therapy of heart failure (CHF). Two years after implantation, the patient experienced recurrent unexpected ICD shocks without clinical symptoms of malignant tachyarrhythmia, or worsened CHF. The patient's condition rapidly worsened, with progressive cardiogenic shock and electrical–mechanical dissociation. After unsuccessful resuscitation of the patient the interrogation of the ICD showed an initial triple counting of extremely wide and fragmented QRS complexes with inappropriate shocks. (PACE 2010; 33:e17–e19)     

An ICD lead with failure of outer insulation goes undetected by regular measurements

We report a patient with ischemic cardiomyopathy status post implantable cardioverter-defibrillator (ICD) implantation in June 2009. Outer insulation failure of her Riata ST ventricular ICD lead goes undetected by routine interrogation and provocative tests as recommended from its manufacturer.(1) Another domain of assessment, fluoroscopy, to facilitate early detection of structural abnormality in this family of ICD lead is discussed.     

Interactions between a Left Ventricular Assist Device and Implantable Cardioverter-Defibrillator

Left ventricular assist devices (LVADs) are approved for both a bridge to cardiac transplantation as well as for destination therapy. Most patients with LVADs have implantable cardioverter-defibrillators (ICDs) and several interactions between LVADs and ICDs have been reported. In the present case, we describe an interaction of an approved LVAD with remote telemetry of a previously implanted Sorin ICD (Sorin Group, Milan, Italy) that could not be resolved with standard shielding techniques. (PACE 2012; 35:e272-e273).     

Plasma renin activity and aldosterone concentration of patients with congestive cardiomyopathy

Blood plasma aldosterone concentration and renin plasma activity were studied in 30 patients with congestive cardiomyopathy and in 41 patients with congestive heart failure resulting from CHD or valvular heart disease using a radio-immunoassay. In congestive cardiomyopathy as well as in congestive heart failure of another etiology an increase in plasma renin activity was noted in single cases in stages IIA and IIB and in most patients with stage III congestive heart failure. Changes in plasma aldosterone concentration with relation to stages of congestive heart failure were unidirectional in both groups of examinees. There was no correlation between plasma renin activity and aldosterone concentration. The study has shown that in congestive cardiomyopathy shifts in the renin-angiotensin-aldosterone system are of the same nature as in patients with congestive heart failure of another etiology.     

Triple Chamber Pacemaker for End-Stage Heart Failure in a Patient with a Previously Implanted Automatic Defibrillator

A 63-year-old man with an ischemic dilated cardiomyopathy previously implanted with an implantable cardioverter defibrillator (ICD) received a triple chamber pacemaker as an ultimate therapeutic resort for end-stage congestive heart failure. After implant, the tolerance to physical exercise increased and NYHA class decreased from III to II. Echocardiography assessed ventricular contraction resynchronization during DDD biventricular pacing as compared to VVI pacing. No major pacemaker-ICD interaction was noted during testing or follow-up. We conclude that sequential biventricular pacing is feasible in the presence of an ICD.     

New onset heart failure in a 29-year-old: A case report of isolated left ventricular noncompaction

A previously healthy 29-year-old patient presented with new onset congestive heart failure. Based on findings on transthoracic echocardiogram (TTE) and cardiac magnetic resonance imaging (MRI) at an outside center, the patient was diagnosed as having a dilated cardiomyopathy with structural abnormalities in the ventricular septum and left ventricular (LV) apex suspicious for myocardial tumor. After referral to our center for further management, repeat TTE revealed findings characteristic of left ventricular non-compaction (LVNC) with severely depressed overall LV systolic function. Review of the outside cardiac MRI supported the diagnosis of LVNC. Final management consisted of traditional medical therapy for congestive heart failure, an implantable cardiac defibrillator (ICD), warfarin anticoagulation for the prevention of thromboembolism and referral for cardiac transplant.     

ICD implantation and arrhythmia-free survival in patients with depressed LV function following surgery for valvular heart disease

Background: Although prophylactic implantable cardioverter‐defibrillator (ICD) implantation is beneficial in patients with severe ischemic cardiomyopathy, it is unclear whether patients with cardiomyopathy due to valvular heart disease have a similar benefit. Methods: We followed 17 patients (14 men/three women, age 62 ± 13 years, left ventricular ejection fraction [LVEF] 29 ± 10%) who had nonischemic valvular cardiomyopathy, underwent valvular heart surgery (aortic valve replacement, mitral valve replacement, and/or mitral valve repair), and subsequently had an electrophysiology study (EPS), for a median of 2.8 years. These patients were compared with 34 patients with prior myocardial infarction and no significant valvular heart disease, who were matched (1:2) for age, gender, LVEF, EPS result, T‐wave alternans result, and ICD placement. Occurrence of arrhythmias was ascertained from ICD device clinic follow‐up and vital status was determined using the National Death Index. Results: There were no differences between the groups in overall survival (P = 0.24) or arrhythmia‐free survival (P = 0.38), and the 2‐year arrhythmia‐free survival was 82% for the valvular patients versus 73% for the ischemic patients. Among patients with ICDs, there was no difference between the groups in overall survival (P = 0.34), time to first appropriate ICD therapy (P = 0.54), and arrhythmia‐free survival (P = 0.51). Conclusion: Patients with valvular cardiomyopathy and residual left ventricular dysfunction following valvular surgery who underwent a tailored approach to ICD implantation had similar overall and arrhythmia‐free survival as patients with ischemic cardiomyopathy.     

Hyperkalemia diagnosed by implantable cardioverter defibrillator T wave sensing

A patient with congestive heart failure and an ICD had undergone atrioventricular nodal ablation and optimization of heart failure medical therapy. Intracardiac T wave sensing by the ICD drew attention to the new development of asymptomatic hyperkalemia. Surface ECG features of hyperkalemia were not readily identified due to pacemaker dependence.     

Heart failure complicated by atrial fibrillation: mechanistic,prognostic, and therapeutic implications

Atrial fibrillation and congestive heart failure are two distinct clinical entities that are responsible for significant morbidity and mortality in the Western world. Hypertension, coronary artery disease, and nonischemic cardiomyopathy represent the most prevalent underlying pathologies of both diseases, implying a coincidence of both in many patients. The prevalence of atrial fibrillation with a progressive degree of congestive heart failure is increasing, as judged by New York Heart Association functional class. Moreover, the presence of congestive heart failure has been identified as one of the most powerful independent predictors of atrial fibrillation, with a sixfold increase in relative risk of its development. On the other hand, atrial fibrillation can cause or significantly aggravate symptoms of congestive heart failure in previously asymptomatic or well-compensated patients. In some patients, symptomatic dilated cardiomyopathy may develop over time entirely due to atrial fibrillation with rapid ventricular rates. Upon restoration of sinus rhythm, this type of "tachymyopathy" has been shown to be often reversible. Recent investigations of the physiologic and structural changes of the atrial myocardium ("electrical and structural remodeling") have shown that neurohumoral activation, fibrosis, and apoptosis are demonstrable with both diseases. On the other hand, experimental data suggest that the substrates of atrial fibrillation in congestive heart failure are different from those of pure atrial tachycardia-related forms of atrial fibrillation. This review highlights the clinical and pathophysiologic similarities and differences of atrial fibrillation and congestive heart failure relevant to the understanding, treatment, and prevention of these diseases in the population at risk.     

Complete loss of ICD programmability after magnetic resonance imaging

The purpose of this case report is to describe the effects of an MRI performed on a patient without realizing that an ICD has been previously implanted. After a few seconds of imaging the adversity was recognized and the examination was stopped immediately. The patient was not pacemaker dependent and had neither physical complaints nor electrocardiographic changes in the surface ECG. A consecutively performed ICD assessment showed a backup mode with standard parameters for pacing (VVI 50 beats/min) and arrhythmia detection and treatment. The device could not be programmed by the external programmer. With the exception of printing out the parameters, all software functions were no longer feasible. A device examination by the manufacturer after ICD replacement showed that a major portion of the device memory was corrupt. Even ICDs of a newer generation are susceptible to magnetic interference, with the danger of complete loss of programmability.     

Long-term outcomes of a telephone intervention after an ICD

BACKGROUND: The purpose of this study was to determine the long-term benefits of participating in a structured, 8-week educational telephone intervention delivered by expert cardiovascular nurses post-ICD. The intervention was aimed to (1) increase physical functioning, (2) increase psychological adjustment, (3) improve self-efficacy in managing the challenges of ICD recovery, and (4) lower levels of health care utilization over usual care in the first 12 months post-ICD. This article reports on the 6- and 12-month outcomes of the nursing intervention trial. METHODS AND RESULTS: A two-group (N = 168) randomized control group design was used to evaluate intervention efficacy with persons receiving an ICD for the secondary prevention of sudden cardiac arrest. Measures were obtained at baseline, 6 and 12 months post hospitalization. Outcomes included (1) physical functioning (Patient Concerns Assessment [PCA], Short Form Health Survey [SF-12], ICD shocks), (2) psychological adjustment (State-Trait Anxiety Inventory [STAI], Centers for Epidemiologic Studies-Depression [CES-D], fear of dying), (3) self-efficacy (Sudden Cardiac Arrest-Self-Efficacy [SCA-SE], Sudden Cardiac Arrest-Behavior [SCA-B], Sudden Cardiac Arrest-Knowledge [SCA-K]), and (4) health care utilization (emergency room [ER] visits, outpatient visits, hospitalizations). Using repeated measures ANOVA, the 6- and 12-month benefits of the intervention over usual care were in reductions in physical concerns (P = 0.006), anxiety (P = 0.04), and fear of dying (P = 0.01), with enhanced self-confidence (P = 0.04) and knowledge (P = 0.001) to manage ICD recovery. There were no statistically significant differences between the groups on total outpatient visits, hospitalizations, or ER visits over 12 months. CONCLUSION: A structured 8-week post-hospital telephone nursing intervention after an ICD had sustained 12-month improvements on patient concerns, anxiety, fear of dying, self-efficacy, and knowledge. Results may not apply to individuals with congestive heart failure who receive an ICD for primary prevention of sudden cardiac arrest.     

Prognosis of hypertrophic and dilated cardiomyopathy

Hypertrophic and dilated cardiomyopathies are a heterogeneous disease, both clinically and genetically. Hypertrophic cardiomyopathy(HCM) is important causes of sudden cardiac death and death from congestive heart failure, although HCM has a relatively benign prognosis. The prognosis of dilated cardiomyopathy(DCM) has improved due to advances in earlier diagnosis and therapy, however, sudden cardiac death and death from congestive heart failure still occur in DCM. Accordingly, it is of importance to know possible risk factors on risk stratification for a high-risk group in HCM and DCM. Possible risk factors may contribute to the construction of therapeutic strategies for the prevention of sudden cardiac death or death from congestive heart failure in patients with HCM and DCM.     

Hypertrophic cardiomyopathy and symptomatic conduction system disease in cardiac amyloidosis

Cardiac involvement is the most important prognostic factor in primary amyloidosis (AL). The clinical presentation of amyloid cardiomyopathy is varied and may manifest as heart failure, brady or tachyarrhythmias, syncope, angina and rarely with features of hypertrophic cardiomyopathy and advanced symptomatic conduction system disease. The management of amyloid cardiomyopathy has always been a dilemma, as most of the drugs used in congestive heart failure are contraindicated. This report describes a 70-year-old woman who presented with syncope, severe diastolic heart failure, features of hypertrophic cardiomyopathy and severe symptomatic conduction system disease requiring a pacemaker. Amyloidosis was diagnosed on endomyocardial biopsy after abdominal fat aspirate was negative for amyloid. The patient eventually expired due to end-stage congestive heart failure.     

End-of-life decisions in ICD patients with malignant tumors

BACKGROUND: The results of multiple implantable cardioverter-defibrillator (ICD) studies have demonstrated a survival benefit in specific high-risk populations, leading to the expansion of ICD implantation rates worldwide. Because the ICD reduces the incidence of sudden cardiac death, patients with these devices more often die of non-arrhythmic causes. For those with a malignancy, little is known about their preferences for disabling ICD therapy. METHODS: The objective of the present study was to evaluate whether patients with an ICD and a malignant tumor desire deactivation of their ICD in order to have a death without ICD interventions, which are life-prolonging, bothersome, and prevent a peaceful death. All deceased patients having had an ICD implanted at our institution were retrospectively analyzed with respect to whether the option of disabling ICD therapy had been discussed and whether the ICD had been deactivated. RESULTS: Two hundred and seventy-two patients received an ICD at our institution between January 1, 1994, and January 31, 2007. Thirty-six of the patients have died, and of these eight had a malignant tumor. In six of these eight patients (75%) the option of disabling their ICD therapy was discussed extensively; none wished to abandon the possibility of terminating a malignant arrhythmia by the ICD. CONCLUSIONS: With the use of ICDs, patients with heart failure are more frequently protected from arrhythmic death, and consequently treating physicians are increasingly confronted with ICD patients presenting with a malignant tumor or other noncardiac terminal disease. In these situations, dialogue between the treating physician and the patient about the possibility of withdrawing ICD therapy is important to terminal care. The physician must be aware that the patient's attitude may contrast with his/her own, and that the patient may be resolute in maintaining ICD protection from arrhythmic death.     

Inappropriate ICD therapy due to proarrhythmic ICD shocks and hyperpolarization

A 50-year-old man with an ischemic cardiomyopathy underwent ICD implantation for inducible ventricular fibrillation (VF). Sixteen months later he experienced inappropriate ICD therapy due to atrial fibrillation with a rapid ventricular response. The initial shock resulted in the initiation of VF (proarrhythmia) and the patient received an additional shock converting his rhythm to an idioventricular rhythm with a cycle length of 490 ms (122 beats/min). Due to lead hyperpolarization, the device oversensed ventricular events and the patient subsequently received additional shocks.     

Surgical ventricular restoration

Surgical left ventricular restoration has been introduced to reshape the dilated cardiac chamber and improve cardiac function for patients with severe congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy. The operations for ischemic cardiomyopathy (Dor, SAVER, etc) provide significant improvements of cardiac function and good short- and long-term survival. Ongoing prospective study (STICH trial) may make those more standard procedures. On the contrary, the operation for idiopathic dilated cardiomyopathy (Batista procedure) carries high risks of operative mortality and recurrence of congestive heart failure. Modifications of operative indications and surgical techniques are under investigation.     

Left ventricular assist devices in heart failure

End-stage heart failure is an ever-growing and devastating disease. The median survival for patients with heart failure on ionotropic support alone is a meager 6 months. Historically, the only option for these patients was to be listed for heart transplantation. Out of medical necessity, the idea of left ventricular assist device (LVAD) as a bridge to transplantation was born. Since their approval by the US FDA, LVADs have quadrupled the survival in patients with heart failure. The increase in survival has also been accompanied by decreased perioperative morbidity, better biocompatibility and longer device life over first-generation LVADs. Undoubtedly, LVADs have changed the landscape of heart failure treatment and will continue to do so in the foreseeable future. In this review, we will highlight the landmark studies that have established LVADs as a therapeutic option for heart failure, as well as reviewing the current LVADs available and speculating on the advancements that will be made in the upcoming years.     

Myocardial scar extent evaluated by cardiac magnetic resonance imaging in ICD patients: relationship to spontaneous VT during long-term follow-up

Patients with ischemic cardiomyopathy have an increased risk for ventricular arrhythmia, since myocardial infarction can be the substrate for re-entrant arrhythmias. Contrast-enhanced cardiac magnetic resonance imaging (CMR) has proven to reliably quantify myocardial infarction. Aim of our study was to evaluate correlations between functional and contrast-enhanced CMR findings and spontaneous ventricular tachy-arrhythmias in patients with ischemic cardiomyopathy who underwent implantable cardioverter-defibrillator (ICD) therapy. Forty-one patients with ischemic cardiomyopathy and indication for ICD therapy underwent cine and late gadolinium enhancement CMR for quantification of left ventricular volumes, function and scar tissue before subsequent implantation of ICD device. During a follow-up period of 1184 ± 442 days 68 monomorphic and 14 polymorphic types of ventricular tachycardia (VT) could be observed in 12 patients. Patients with monomorphic VT had larger scar volumes (25.3 ± 11.3 vs. 11.8 ± 7.5% of myocardial mass, P < 0.05) than patients with polymorphic VT. Moreover myocardial infarction involved more segments in the LAD perfusion territory (86 vs. 20%, P < 0.05) than in patients with polymorphic VT. Patients with spontaneous monomorphic VT during the long-term follow-up period had more infarcted tissue, which was more often present in the LAD perfusion territory than patients with polymorphic events. These data strengthen the diagnostic benefit of CMR in patients with ischemic cardiomyopathy. CMR may be used for better risk stratification in patients with ischemic cardiomyopathy undergoing ICD therapy.