An alternating QRS: How does it go even though it's pretty slow?

We present the case of a 42 year old patient with a history of childhood lymphoma treated with chemotherapy and radiation who underwent combined aortic and mitral valve replacements and who postoperatively developed an interesting ECG which showed complete heart block and an alternating left bundle branch and narrow complex QRS pattern at a heart rate of 69 beats per minute (bpm). We discuss potential mechanisms for this interesting pattern.

Ventricular Arrhythmia in Cancer Patients: Mechanisms, Treatment Strategies and Future Avenues.

Cardiovascular disease and cancer are the leading causes of morbidity and mortality in the US. Despite the significant progress made in cancer treatment leading to improved prognosis and survival, ventricular arrhythmias (VA) remain a known cardiovascular complication either exacerbated or induced by the direct and indirect effects of both traditional and novel cancer treatments. Although interruption of cancer treatment because of VA is rarely required, knowledge surrounding this issue is essential for optimising the overall care of patients with cancer. The mechanisms of cancer-therapeutic-induced VA are poorly understood. This review will discuss the ventricular conduction (QRS) and repolarisation abnormalities (QTc prolongation), and VAs associated with cancer therapies, as well as existing strategies for the identification, prevention and management of cancer-treatment-induced VAs.

Multidisciplinary Management of Opioid Use-Related Infective Endocarditis: Treatment, QTc Values, and Cardiac Arrests due to Ventricular Fibrillation.

(1) Background: The opioid epidemic has led to an increase in cardiac surgery for infective endocarditis (IE-CS) related to injection use of opioids (OUD) and other substances and a call for a coordinated approach to initiate substance use disorder treatment, including medication for OUD (MOUD), during IE-CS hospitalizations. We sought to determine the effects of the initiation of a multi-disciplinary endocarditis evaluation team (MEET) on MOUD use, electrocardiographic QTc measurements and cardiac arrests due to ventricular fibrillation (VF) in patients with OUD. (2) Methods and Results: A historical group undergoing IE-CS at Yale-New Haven Hospital prior to MEET initiation, Group I (43 episodes of IE-CS, 38 patients) was compared to 24 patients undergoing IE-CS after MEET involvement (Group II). Compared to Group l, Group II patients were more likely to receive MOUD (41.9 vs. 95.8%, p < 0.0001), predominantly methadone (41.9 vs. 79.2%, p = 0.0035) at discharge. Both groups had similar QTcs: approximately 30% of reviewed electrocardiograms had QTcs ≥ 470 ms and 17%, QTcs ≥ 500 ms. Cardiac arrests due to VF were not uncommon: Group I: 9.3% vs. Group II: 8.3%, p = 0.8914. Half occurred in the 1-2 months after surgery and were contributed to by pacemaker malfunction/ management and half were related to opioid use. (3) Conclusions: MEET was associated with increased MOUD (predominantly methadone) use during IE-CS hospitalizations without an increase in QTc prolongation or cardiac arrest due to VF compared to Group I, but events occurred in both groups. These arrests were associated with pacemaker issues or a return to opioid use. Robust follow-up of IE-CS patients is essential, as is further research to clarify the longer-term effects of MEET on outcomes.

Arrhythmias in Cardiac Sarcoidosis Bench to Bedside: A Case-Based Review.

Cardiac sarcoidosis is a component of an often multiorgan granulomatous disease of still uncertain cause. It is being recognized with increasing frequency, mainly as the result of heightened awareness and new diagnostic tests, specifically cardiac magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography scans. The purpose of this case-based review is to highlight the potentially life-saving importance of making the early diagnosis of cardiac sarcoidosis using these new tools and to provide a framework for the optimal care of patients with this disease. We will review disease mechanisms as currently understood, associated arrhythmias including conduction abnormalities, and atrial and ventricular tachyarrhythmias, guideline-directed diagnostic criteria, screening of patients with extracardiac sarcoidosis, and the use of pacemakers and defibrillators in this setting. Treatment options, including those related to heart failure, and those which may help clarify disease mechanisms are included.

Survival Following Implantable Cardioverter-Defibrillator Implantation in Patients With Amyloid Cardiomyopathy.

Background Outcomes data in patients with cardiac amyloidosis after implantable cardioverter-defibrillator (ICD) implantation are limited. We compared outcomes of patients with ICDs implanted for cardiac amyloidosis versus nonischemic cardiomyopathies (NICMs) and evaluated factors associated with mortality among patients with cardiac amyloidosis. Methods and Results Using National Cardiovascular Data Registry's ICD Registry data between April 1, 2010 and December 31, 2015, we created a 1:5 propensity-matched cohort of patients implanted with ICDs with cardiac amyloidosis and NICM. We compared mortality between those with cardiac amyloidosis and matched patients with NICM using Kaplan-Meier survival curves and Cox proportional hazards models. We also evaluated risk factors associated with 1-year mortality in patients with cardiac amyloidosis using multivariable Cox proportional hazards regression models. Among 472 patients with cardiac amyloidosis and 2360 patients with propensity-matched NICMs, 1-year mortality was significantly higher in patients with cardiac amyloidosis compared with patients with NICMs (26.9% versus 11.3%, P<0.001). After adjustment for covariates, cardiac amyloidosis was associated with a significantly higher risk of all-cause mortality (hazard ratio [HR], 1.80; 95% CI, 1.56-2.08). In a multivariable analysis of patients with cardiac amyloidosis, several factors were significantly associated with mortality: syncope (HR, 1.78; 95% CI, 1.22-2.59), ventricular tachycardia (HR, 1.65; 95% CI, 1.15-2.38), cerebrovascular disease (HR, 2.03; 95% CI, 1.28-3.23), diabetes mellitus (HR, 1.55; 95% CI, 1.05-2.27), creatinine = 1.6 to 2.5 g/dL (HR, 1.99; 95% CI, 1.32-3.02), and creatinine >2.5 (HR, 4.34; 95% CI, 2.72-6.93). Conclusions Mortality after ICD implantation is significantly higher in patients with cardiac amyloidosis than in patients with propensity-matched NICMs. Factors associated with death among patients with cardiac amyloidosis include prior syncope, ventricular tachycardia, cerebrovascular disease, diabetes mellitus, and impaired renal function.

The Heart Rhythm Society/American College of Physicians Atrial Fibrillation Screening and Education Initiative.

BACKGROUND: The prevalence of both atrial fibrillation (AF) and stroke is increasing. Stroke is common in AF and can have devastating consequences, especially when AF is unrecognized and anticoagulation is not initiated. OBJECTIVE: The purpose of this study was to demonstrate the feasibility and yield, both in identifying previously undiagnosed AF and in educating patients and caregivers about AF, of systematic screening events in internal medicine practices using a mobile electrocardiogram device (Kardia/AliveCor iECG). METHODS: With support from the Heart Rhythm Society and the American College of Physicians, 5 internal medicine practices performed systematic screening and education of patients at higher risk of AF using the Kardia/AliveCor device and a variety of educational materials. Patients screened as "unclassified" or "possible AF" were referred for further evaluation. Patients and providers (physicians, nurses, and allied professionals) assessed the screening process. RESULTS: A total of 772 patients were screened. The mean age was 65.2 ± 15.4 years, and 281 (28.2%) were 75 years or older. The majority, 521 (67.5%), were female, and 586 (75.7%) had a CHA2DS2-VASc score of ≥2. Six hundred seventy patients (86.8%) were screened as "normal," 85 (11.0%) as "unclassified," and 17 (2.2%) as "possible AF." Participants demonstrated a significant knowledge deficit about stroke and AF before the screening events, and the majority felt that their awareness of these issues increased significantly as a result of their participation. CONCLUSION: This collaborative Heart Rhythm Society/American College of Physicians systematic screening effort using the Kardia/AliveCor device was feasible. Although it resulted in a relatively modest yield of "unclassified" or "possible AF" screens, it had significant educational benefit to participants and caregivers. The diagnostic yield of future programs could be enriched by including more elderly patients and those with more risk factors for AF and stroke. A greater duration or frequency of monitoring would likely increase sensitivity but be more complicated and costlier to administer. Future events should include on-site confirmatory testing with a 12-lead electrocardiogram. Devices such as the Kardia/AliveCor monitor may enhance patient engagement in screening programs.

Late recovery of surgically-induced atrioventricular block in patients with congenital heart disease.

OBJECTIVES: To assess the incidence and establish possible predictors of late recovery of post-surgical heart block, treated with pacemaker implantation, in patients with congenital heart defects. BACKGROUND: The American College of Cardiology/American Heart Association Task Force has recommended pacemaker implantation for advanced second or third degree atrioventricular block which persists for 7 to 14 days after surgery. The incidence of late recovery of post-surgical heart block following pacemaker implantation has not been reported. METHODS: Records of 44 patients with post-surgical heart block who underwent pacemaker implantation at our institutions since 1976 were reviewed for demographic, anatomic, surgical and surface electrocardiographic data to assess the incidence of, and factors associated with, recovery of atrioventricular conduction on long-term follow-up. RESULTS: 32% (14) of patients recovered atrioventricular conduction at a median follow-up of 5.5 years while 68% (30) remained pacemaker dependent. The groups were similar in age and weight at surgery and period of follow-up p = 0.5). Types of defect and surgical repair were not significantly different (p > 0.1). There was a similar number of patients with second degree-type II block in both groups (p = 0.15). The groups did not differ in timing of pacemaker implantation (<10 days p = 0.14, >14 days p = 0.18). CONCLUSIONS: Late recovery of atrioventricular conduction following pacemaker implantation for postsurgical heart block is common. However, clinical predictors, with reference to current recommendations, could not be identified. Prospective electrophysiologic evaluations may be warranted to establish guidelines for long term pacemaker dependency and criteria for pacing.