Deshmukh, Abhishek

Abstract The primary goal of the initial ECG evaluation of every wide complex tachycardia is to determine whether the tachyarrhythmia has a ventricular or supraventricular origin. The answer to this question drives immediate patient care decisions, ensuing clinical workup, and long‐term management strategies. Thus, the importance of arriving at the correct diagnosis cannot be understated and has naturally spurred rigorous research, which has brought forth an ever‐expanding abundance of manually applied and automated methods to differentiate wide complex tachycardias. In this review, we provide an in‐depth analysis of traditional and more contemporary methods to differentiate ventricular tachycardia and supraventricular wide complex tachycardia. In doing so, we: (1) review hallmark wide complex tachycardia differentiation criteria, (2) examine the conceptual and structural design of standard wide complex tachycardia differentiation methods, (3) discuss practical limitations of manually applied ECG interpretation approaches, and (4) highlight recently formulated methods designed to differentiate ventricular tachycardia and supraventricular wide complex tachycardia automatically.

Abstract Background Hypothyroidism is known to be associated with adverse clinical outcomes in heart failure. The association between hypothyroidism and cardiac resynchronization therapy outcomes in patients with severe heart failure is not clear. Methods The study included 1,316 patients who received cardiac resynchronization therapy between 2002 and 2015. Baseline demographics and cardiac resynchronization therapy outcomes, including left ventricular ejection fraction, New York Heart Association class, appropriate implantable cardioverter-defibrillator therapy, and all-cause mortality, were collected from the electronic health record. Results Of the study cohort, 349 patients (26.5%) were classified as the hypothyroidism group. The median duration of follow-up was 3.6 years (interquartile range, 1.7-6.2). Hypothyroidism was associated with a greater all-cause mortality than euthyroidism (hazard ratio, 1.19; 95% CI, 1.01-1.38; P=0.04). In this group, the risk of appropriate implantable cardioverter-defibrillator therapy significantly increased in association with increased baseline thyroid-stimulating hormone level (hazard ratio, 1.27 per 5 mIU/L increase, 95% CI, 1.00-1.53, P=0.04). Conclusions Cardiac resynchronization therapy improves cardiac function in hypothyroid patients. Hypothyroidism has adverse effects on cardiac resynchronization therapy outcomes with reduced survival and increased implantable cardioverter-defibrillator therapies for ventricular arrhythmic events.

AbstractBackgroundUtilization of catheter ablation of ventricular tachycardia (VT) has steadily increased in recent years. Exploring short‐term outcomes is vital in health care planning and resource allocation.MethodsThe Nationwide Readmissions Database from 2010 to 2014 was queried using the ICD‐9 codes for VT (427.1) and catheter ablation (37.34) to identify study population. Incidence, causes of 30‐day readmission, in‐hospital complications as well as predictors of 30‐day readmissions, complications, and cost of care were analyzed.ResultsAmong 11 725 patients who survived to discharge after index admission for VT ablation, 1911 (16.3%) were readmitted within 30 days. Paroxysmal VT was the most common cause of 30‐day readmission (39.51%). Dyslipidemia, chronic kidney disease (CKD), previous CABG, congestive heart failure (CHF), chronic pulmonary disease, and anemia predicted increased risk of 30‐day readmissions. The overall in‐hospital complication rate was 8.2% with vascular and cardiac complications being the most common. Co‐existing CKD and CHF and the need for mechanical circulatory support (MCS) predicted higher complication rates. Similarly increasing age, CKD, CHF, anemia, in‐hospital use of MCS or left heart catheterization, teaching hospital, and disposition to nursing facilities predicted higher cost.ConclusionApproximately one in six patients was readmitted after VT ablation, with paroxysmal VT being the most common cause of the readmission. A complication rate of 8.2% was noted. We also identified a predictive model for increased risk of readmission, complication, and factors influencing the cost of care that can be utilized to improve the outcomes related to VT ablation.

AbstractIntroductionThe ablation of outflow tract premature ventricular contractions (PVCs) is generally safe and effective. In some patients, successful ablation sites may not correlate with the earliest activation. We sought to evaluate mechanistic and anatomic relevance of the region below the left sinus of Valsalva in variable morphology outflow tract ventricular arrhythmias.MethodsPVC cases where ablation was in the region inferior to the left sinus of Valsalva were identified. Procedural and demographic information and long‐term outcomes were obtained. Cadaver dissections to evaluate regional anatomy were done as well.ResultsA total of 51 cases were included (age 53 ± 10; 37 [73%] males). Ablation was done for high PVC burden (>20%; mean 27% ± 8%) and presence of symptoms (73%) or ejection fraction less than 50% (78%). QRS morphology included either R wave (8; 16%), Rs (9; 18%), or rS (67%) in lead I, no precordial transition (40; 78%), V2 transition, (7; 14%), or V3 transition (4; 8%). In 31 (61%), the site just below the left coronary cusp was the earliest site, while the remainder had another site earlier. Ablation was acutely successful in 50 of 51 (98%). After 3 months, success was noted in 48 of 51 (94%). In two patients, repeat ablation in the same region resulted in durable suppression.ConclusionThe cases presented emphasize the importance of a region centered below the left sinus of Valsalva, where multivariable morphology QRS may be successfully ablated. Consideration of mapping and ablation even when signals are late in this region may be warranted in previously failed ablation attempts or first‐line evaluation.

AbstractBackgroundThe accurate separation of undifferentiated wide complex tachycardias (WCTs) into ventricular tachycardia (VT) or supraventricular wide complex tachycardia (SWCT) using conventional, manually‐applied 12‐lead electrocardiogram (ECG) interpretation methods is difficult.PurposeWe sought to devise a new WCT differentiation method that operates solely on automated measurements routinely provided by computerized ECG interpretation software.MethodsIn a two‐part analysis, we developed and validated a logistic regression model (ie, VT Prediction Model) that utilizes routinely available computerized measurements derived from patients' paired WCT and baseline ECGs.ResultsThe derivation cohort consisted of 601 paired WCT (273 VT, 328 SWCT) and baseline ECGs from 421 patients. The VT Prediction Model, composed of WCT QRS duration (ms) (P < .0001), QRS duration change (ms) (P < .0001), QRS axis change (°) (P < .0001) and T axis change (°) (P < .0001), yielded effective VT and SWCT differentiation (area under the curve [AUC]: 0.924; confidence interval [CI]: 0.903‐0.944) for the derivation cohort. The validation cohort comprised 241 paired WCT (97 VT, 144 SWCT) and baseline ECGs from 177 patients. The VT Prediction Model's implementation on the validation cohort yielded effective WCT differentiation (AUC: 0.900; CI: 0.862‐0.939) with overall accuracy, sensitivity, and specificity of 85.0%, 80.4%, and 88.2%, respectively.ConclusionThe VT Prediction Model is an example of how readily available ECG measurements may be used to distinguish VT and SWCT effectively. Further study is needed to develop and refine newer WCT differentiation approaches that utilize computerized measurements provided by ECG interpretation software.

Background Atrial fibrillation is the most common arrhythmia worldwide. Data regarding 30‐day readmission rates after discharge for atrial fibrillation remain poorly reported. Methods and Results The Nationwide Readmission Database (2010–2014) was queried using the International Classification of Diseases, Ninth Revision ( ICD‐9 ) codes to identify study population. Incidence, etiologies of 30‐day readmission and predictors of 30‐day readmissions, and cost of care were analyzed. Among 1 723 378 patients who survived to discharge, 249 343 (14.4%) patients were readmitted within 30 days. Compared with the readmitted group, the nonreadmitted group had higher utilization of electrical cardioversion and catheter ablation. Atrial fibrillation was the most common cause of readmission (24.1%). Median time to 30‐day readmission was 13 days. Advancing age, female sex, and longer stay during index hospitalization predicted higher 30‐day readmissions, whereas private insurance, electrical cardioversion, catheter ablation, higher income, and elective admissions correlated with lower 30‐day readmission. Comorbidities such as heart failure, neurological disorder, chronic obstructive pulmonary disease, diabetes mellitus, chronic kidney disease, chronic liver failure, coagulopathy, anemia, peripheral vascular disease, and electrolyte disturbance, correlated with increased 30‐day readmissions and cost burden. Trend analysis showed a progressive decline in 30‐day readmission rates from 14.7% in 2010 to 14.3% in 2014 ( P trend, <0.001). Conclusions Approximately 1 in 7 patients were readmitted within 30 days of discharge, with symptomatic atrial fibrillation being the most common cause. We identified a predictive model for increased risk of readmissions and treatment expense. Electrical cardioversion during index admission was associated with a significant reduction in 30‐day readmissions and service charges. The 30‐day readmissions correlated with a substantial rise in the cost of care.

Background: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. Methods: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. Results: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P =0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB ( P <0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P =0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P =0.009). There were no procedure-related major complications. Conclusions: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.

AbstractBackgroundThere are few data regarding the outcome of a combined cryo‐ and radiofrequency (RF)‐catheter ablation of various types of supraventricular tachycardias (SVTs) originating from near the normal conduction system.METHODSWe analyzed all patients undergoing combined cryo‐ and RF‐ catheter ablation at Mayo Clinic, Rochester, MN as part of the ablation of SVTs with potential risks of injury to the normal conduction system. This study aimed to assess the outcome of a combined cryo‐ and RF‐catheter ablation of various types of SVTs.RESULTSThe study population consisted of 54 patients (38 ± 17 years, 32 men). A combined cryo‐ and RF‐catheter ablation was attempted for septal accessary pathways (APs) in 26, atrioventricular nodal reentrant tachycardia (AVNRT) in 14, atrial tachycardia (AT) in 7, and junctional ectopic tachycardia in 7 patients. Forty‐one patients (76%) were successfully ablated with cryoablation, and RF ablation after an unsuccessful cryoablation ablated the SVTs successfully at the same location in 6 patients (11%). Complication occurred in 1 patient (deep vein thrombosis). The cumulative freedom from SVT rate at 30 days after the procedure was 78% and there was no significant difference in the recurrence rate among the SVTs.CONCLUSIONA combined cryo‐ and RF‐catheter ablation is clinically effective in patients undergoing SVT ablation with the potential risk of injury to the normal conduction system.

AbstractBackgroundHypertrophic cardiomyopathy (HCM) accounts for significant morbidity and mortality worldwide. Arrhythmias are considered the main cause of mortality, however, there is paucity of data relating to trends of arrhythmia and associated outcomes in HCM patients.MethodsNationwide Inpatient Sample from 2003 to 2014 was analyzed. HCM related hospitalizations were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9‐CM) code 425.1 and 425.11 in all diagnosis fields.ResultsOverall, there was an increase in number of hospitalizations related to arrhythmias among HCM patients from 7784 in 2003 to 8380 in 2014 (relative increase 10.5%, P < 0.001). The increase was most significant in patients ≥ 80 years and those with higher comorbidity burden. Atrial fibrillation (AF) was the most frequently occurring arrhythmia however atrial flutter (AFL) witnessed the highest rise during the study period. In general, there was a down trend in mortality with the greatest reduction occurring in patients with ventricular fibrillation/flutter (VF/VFL). The mean length of stay was higher if patients had arrhythmia, which led to increased cost of care from $16105 in 2003 to $19310 in 2014 (relative increase 22.9%, P < 0.001).ConclusionThere is overall decline in HCM related hospitalizations but rise in hospitalization among HCM patients with arrhythmias. HCM with arrhythmia accounts for significant inpatient mortality coupled with prolonged hospital stay and increased cost of care. However, there is an encouraging downtrend in the mortality most likely because of improved clinical practice, cardiac screening and primary and secondary prevention strategies.