Acute Myocardial Infarction Revealed by an Escape Rhythm in a Patient With Failed Sgarbossa Criteria.

This case report describes a man in his 80s with a medical history of essential hypertension who presented to the emergency department with sudden onset epigastric pain.

Physiologic Variants of Cardiac Conduction (Aberration, Gap, Supernormal Conduction).

Wide QRS complexes during supraventricular rhythms can be caused by fixed bundle branch block, functional (intermittent) bundle branch block, preexcitation, or toxic/metabolic causes. Functional bundle branch block can be caused by long-short aberrancy (usually physiologic), or acceleration/deceleration dependent aberrancy (usually pathologic). Electrocardiogram criteria have been proposed to differentiate aberration from ventricular tachycardia; they are not always accurate. The gap phenomenon "paradox" is that with increasingly premature extrastimuli, progressive proximal conduction delay allows time for distal recovery of excitability. Supernormal conduction may explain unusual conduction phenomena in patients with abnormal His-Purkinje function or poorly conducting accessory pathways.

Thoracoscopic Left Atrial Appendage Exclusion for Atrial Fibrillation Patients Intolerant to Anticoagulation.

OBJECTIVE: Outcomes associated with isolated epicardial left atrial appendage (LAA) exclusion in atrial fibrillation (AF) patients with a contraindication or intolerance to anticoagulation are not clearly defined, especially in patients with prior stroke. This study evaluated the perioperative safety, medication use, and stroke outcomes for isolated thoracoscopic LAA exclusion for stroke prevention. METHODS: A single-center retrospective study was performed of adults undergoing isolated thoracoscopic LAA exclusion with an epicardial exclusion device without a concomitant surgical procedure. Descriptive statistics were performed. RESULTS: Twenty-five patients met the inclusion criteria. The cohort was 68% male (n = 17) with a mean age of 76.4 ± 6.5 years, a mean preoperative CHA2DS2-VASc score of 4.2 ± 1.4, and a mean preoperative HAS-BLED score of 2.68 ± 1.03. Seventeen patients (68%) had nonparoxysmal AF. There were 11 patients with intolerance of anticoagulation due to intracranial hemorrhage (44%), 6 due to gastrointestinal bleeding (24%), and 4 due to genitourinary bleeding (16%). All procedures were performed thoracoscopically with 100% technical success-the mean LAA stump length was 5.5 ± 2.3 mm on intraoperative transesophageal echocardiography. The median hospital length of stay was 2 (interquartile range [IQR] 1, 6.5) days. The median follow-up time was 430 (IQR 125, 972) days. During follow-up, 1 patient with cerebral angiopathy had temporary neurologic deficits at an outside institution, with brain imaging showing no evidence of ischemic injury. There were no other thromboembolic events over the 38.8 postoperative patient-years examined. All patients were off anticoagulation at last follow-up. CONCLUSIONS: This study shows the perioperative safety, technical success, freedom from anticoagulation, and stroke outcomes of isolated thoracoscopic LAA exclusion in patients with AF at high risk for thromboembolic disease.

Progression of ECG in hydroxychloroquine overdose.

Hydroxychloroquine overdose is associated with myocardial toxicity and conduction disorders. We report a case of hydroxychloroquine overdose that demonstrated a rapid progressive intraventricular conduction delay and QT prolongation resulting in significant bradycardia and shock despite aggressive treatment. We describe the rare capture of abrupt abnormalities of this overdose in sequential electrocardiograms in the immediate hours post-ingestion.

Why is the patient still symptomatic after myectomy for HCM!

We describe the case of a young female patient with hypertrophic cardiomyopathy (HCM) with a dual chamber implantable cardioverter defibrillator (ICD), and complete heart block from a prior septal ablation procedure. Due to persistent left ventricular outflow tract (LVOT) obstruction and symptoms, she underwent surgical myectomy. Her exertional symptoms continued despite improved LVOT flow parameters. A comprehensive evaluation, including ICD interrogation, helped arrive at the correct diagnosis and treatment plan.

Physiologic Variants of Cardiac Conduction (Aberration, Gap, Supernormal Conduction).

Wide QRS complexes during supraventricular rhythms can be caused by fixed bundle branch block, functional (intermittent) bundle branch block, preexcitation, or toxic/metabolic causes. Functional bundle branch block can be caused by long-short aberrancy (usually physiologic), or acceleration/deceleration dependent aberrancy (usually pathologic). Electrocardiogram criteria have been proposed to differentiate aberration from ventricular tachycardia; they are not always accurate. The gap phenomenon "paradox" is that with increasingly premature extrastimuli, progressive proximal conduction delay allows time for distal recovery of excitability. Supernormal conduction may explain unusual conduction phenomena in patients with abnormal His-Purkinje function or poorly conducting accessory pathways.

Cardiovascular Considerations for the Internist and Hospitalist in the COVID-19 Era.

It is clear that existing cardiovascular disease is a major risk factor for COVID-19 and related adverse outcomes. In addition to acute respiratory syndrome, a large cohort also develop myocardial or vascular dysfunction, in part from inflammation and renin angiotensin system activation with increased sympathetic outflow, cardiac arrhythmias, ischemia, heart failure, and thromboembolic complications that portend poor outcomes related to COVID-19. We summarize recent information for hospitalists and internists on the front line of this pandemic regarding its cardiovascular impacts and management and the need for cardiovascular consultation.

Minimally invasive thoracoscopic surgery is an effective approach for treating inappropriate sinus tachycardia.

INTRODUCTION: Inappropriate sinus tachycardia (IST) is characterized by increased heart rate out of proportion to normal physiologic demand. IST ablation is challenging for the electrophysiology community due to the epicardial location of the sinus node and the risk of phrenic nerve (PN) injury during catheter ablation. In this study, we investigated the safety and efficacy of a minimally invasive thoracoscopic surgery for elimination of IST. METHODS: Patients with IST who failed medical therapy or endocardial ablation underwent minimally invasive thoracoscopic epicardial ablation. Epicardial activation mapping was performed to identify the earliest activation site and any possible migration of earliest activation along the lateral right atrium. The PN in each patient was protected by a pericardial retraction suture. RESULTS: From 1 January 2000 to 15 June 2018, 10 patients (eight females and two males) underwent minimally invasive thoracoscopic IST ablation. Mean age of the patients was 36.7 ± 12.5 years. Mean baseline sinus rate was 113.8 ± 21.8 beats per minute. After surgery, the mean heart rate significantly decreased to 79.8 ± 8.2 at postoperative day 1 and to 75.8 ± 8.1 at day 30 (both P < .001). No in-hospital death, stroke, or PN injury occurred. One patient required reintubation, one patient developed postoperative pericarditis, and another patient had a pulmonary embolus. Median follow-up was 6 months (range, 1-50). Freedom from reintervention was 88% at 6 months. CONCLUSION: Minimally invasive thoracoscopic ablation for IST is a safe and effective approach that preserves the phrenic nerve. Due to the possibility of IST activation site migration, continued follow-up after surgery is required.

Meta-Analysis Comparing Catheter-Guided Ablation Versus Conventional Medical Therapy for Patients With Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction.

The prognostic benefit of catheter ablation (CA) for atrial fibrillation in the setting of heart failure (HF) with reduced ejection fraction (EF) is unclear. A systematic search of medical literature was limited to randomized controlled trials. The primary outcome was all-cause mortality, and secondary outcomes were HF hospitalizations, stroke, left ventricular EF improvement, change in 6-minute walk test, and change in Minnesota living with HF questionnaire (Δ MLHFQ). Random effects risk ratios (RR) were calculated for categorical outcomes and standardized mean differences (SMD) for continuous ones, using Der-Simonian and Liard model. A total of 775 ambulatory patients from 6 trials were included. The mean EF was 31% with a mean New York Heart Association classification class 2.5. At a mean follow-up of 26 months, CA was associated with lower incidences of all-cause mortality (RR 0.50, 95% confidence intervals [CI] 0.34 to 0.74, I2 = 0%, p <0.0001), and HF hospitalizations (RR 0.58, 95% CI 0.41 to 0.81, p = 0.002, I2 = 0%), with similar incidences of stroke. Left ventricular EF improvement (SMD = 2.58, 95% CI 0.88 to 4.27), and change in Minnesota living with heart failure HF questionnaire (SMD = -0.40, 95% CI -0.65 to -0.14) were also in favor of CA, with no difference noted in change in 6-minute walk test. The incidence of all reported procedural complications (including major and minor) was 7.3%. In conclusion, CA of atrial fibrillation appears to be associated with improved survival and HF hospitalizations compared with medical therapy, with evidence of low ablation-related complications.

Iatrogenic Ventricular Fibrillation after Direct-Current Cardioversion of Preexcited Atrial Fibrillation Caused by Inadvertent T-Wave Synchronization.

Direct-current cardioversion is an important means of managing arrhythmias. During treatment, carefully synchronizing energy delivery to the QRS complex is necessary to avoid ventricular fibrillation caused by a shock during the vulnerable period of ventricular repolarization, that is, a shock on the T wave. The presence of an accessory pathway and ventricular preexcitation can lead to difficulty in distinguishing the QRS complex from the T wave because of bizarre, wide, irregular QRS complexes and prominent repolarization. We present the cases of 2 patients who had iatrogenic ventricular fibrillation from inappropriate T-wave synchronization during direct-current cardioversion of preexcited atrial fibrillation. Our experience shows that rapidly recognizing the iatrogenic cause of VF and immediate treatment with unsynchronized defibrillation can prevent adverse clinical outcomes.

Thoracoscopic Ablation With Appendage Ligation Versus Medical Therapy for Stroke Prevention: A Proof-of-Concept Randomized Trial.

OBJECTIVE: Atrial fibrillation (AF) has a demonstrable effect on quality of life (QOL). Recurrent stroke occurs in 10% of patients with AF. The objective of this study was to demonstrate proof of concept that thoracoscopic pulmonary vein isolation and atrial appendage ligation (TPVIAL) could prevent recurrent stroke and could potentially improve QOL in patients with AF with a previous stroke. METHODS: The study was a National Institutes of Health-funded single-center proof-of-concept design that randomized 23 patients with AF-related stroke to TPVIAL (n = 12) or to medical management (n = 11). Quality of life was the primary outcome variable; secondary end points included restoration of rhythm, recurrent stroke, and surgical morbidity. RESULTS: Quality-of-life subscores at 3 and 6 months revealed improvements in energy and decreases in fatigue in the TPVIAL arm [baseline, 33 (19.8); 3 months, 49.5 (20.6), P = 0.01; 6 months, 55.5 (14.4), P = 0.03]. At 12-month follow-up, there were no recurrent strokes in the TPVIAL group. In the medically treated arm, two patients at 6 months (P = 0.22) and three total patients at 12 months (P = 0.09) had recurrent ischemic stroke. There was one death in the medical management arm. In the TPVIAL arm, no AF recurrence occurred in patients with paroxysmal AF, and one patient had recurrence of persistent and long-standing AF. Seven patients in the TPVIAL arm discontinued warfarin therapy for secondary stroke prevention. CONCLUSIONS: This small proof-of-concept study showed that TPVIAL improved QOL on two subscores and restored normal sinus rhythm in all but one patient, and it showed the potential to prevent secondary stroke. A larger study will be needed.

Lead astray: minimally invasive removal of a pacing lead in the left ventricle.

Pacemaker and implantable cardioverter defibrillator (ICD) leads are placed routinely with few notable complications. A rarely described complication of transvenous lead placement is malpositioning into the left ventricle. This situation can cause additional complications in the form of thromboembolic events. We present a case of a malpositioned left ventricular lead that was successfully removed with a minimally invasive technique.