Familial Hypertrophic Cardiomyopathy With Fasciculoventricular Accessory Pathway.

Hypertrophic cardiomyopathy (HCM) is a common but an underdiagnosed condition. Fasciculoventricular bypass tract (FVBT) is rare. Concomitant presence of both conditions is well described in Danon disease. We report a case of familial HCM with FVBT linked to a heterozygous pathogenic variant, c.655G>C (p.Val219Leu), in the cardiac myosin binding protein C3 (MYBPC3) gene. (Level of Difficulty: Advanced.).

Exhaled VOCs can discriminate subjects with COVID-19 from healthy controls.

COVID-19 detection currently relies on testing by reverse transcription polymerase chain reaction (RT-PCR) or antigen testing. However, SARS-CoV-2 is expected to cause significant metabolic changes in infected subjects due to both metabolic requirements for rapid viral replication and host immune responses. Analysis of volatile organic compounds (VOCs) from human breath can detect these metabolic changes and is therefore an alternative to RT-PCR or antigen assays. To identify VOC biomarkers of COVID-19, exhaled breath samples were collected from two sample groups into Tedlar bags: negative COVID-19 (n= 12) and positive COVID-19 symptomatic (n= 14). Next, VOCs were analyzed by headspace solid phase microextraction coupled to gas chromatography-mass spectrometry. Subjects with COVID-19 displayed a larger number of VOCs as well as overall higher total concentration of VOCs (p< 0.05). Univariate analyses of qualified endogenous VOCs showed approximately 18% of the VOCs were significantly differentially expressed between the two classes (p< 0.05), with most VOCs upregulated. Machine learning multivariate classification algorithms distinguished COVID-19 subjects with over 95% accuracy. The COVID-19 positive subjects could be differentiated into two distinct subgroups by machine learning classification, but these did not correspond with significant differences in number of symptoms. Next, samples were collected from subjects who had previously donated breath bags while experiencing COVID-19, and subsequently recovered (COVID Recovered subjects (n= 11)). Univariate and multivariate results showed >90% accuracy at identifying these new samples as Control (COVID-19 negative), thereby validating the classification model and demonstrating VOCs dysregulated by COVID are restored to baseline levels upon recovery.

Clinical Benefit of Ablating Localized Sources for Human Atrial Fibrillation: The Indiana University FIRM Registry.

BACKGROUND: Mounting evidence shows that localized sources maintain atrial fibrillation (AF). However, it is unclear in unselected "real-world" patients if sources drive persistent atrial fibrillation (PeAF), long-standing persistent atrial fibrillation (LPeAF), or paroxysmal atrial fibrillation (PAF); if right atrial sites are important; and what the long-term success of source ablation is. OBJECTIVES: The aim of this study was to analyze the role of rotors and focal sources in a large academic registry of consecutive patients undergoing source mapping for AF. METHODS: One hundred seventy consecutive patients (mean age 59 ± 12 years, 79% men) with PAF (37%), PeAF (31%), or LPeAF (32%). Of these, 73 (43%) had undergone at least 1 prior ablation attempt (mean 1.9 ± 0.8; range: 1 to 4). Focal impulse and rotor modulation (FIRM) with an endocardial basket catheter was used in all cases. RESULTS: FIRM analysis revealed sources in the right atrium in 85% of patients (1.8 ± 1.3) and in the left atrium in 90% of patients (2.0 ± 1.3). FIRM ablation terminated AF to sinus rhythm or atrial flutter or tachycardia in 59% (PAF), 37% (PeAF), and 19% (LPeAF) of patients, with 15 of 67 terminations due to right atrial ablation. On follow-up, freedom from AF after a single FIRM procedure for the entire series was 95% (PAF), 83% (PeAF), and 82% (LPeAF) at 1 year and freedom from all atrial arrhythmias was 77% (PAF), 75% (PeAF), and 57% (LPeAF). CONCLUSIONS: In the Indiana University FIRM registry, FIRM-guided ablation produced high single-procedure success, mostly in patients with nonparoxysmal AF. Data from mapping, acute terminations, and outcomes strongly support the mechanistic role of biatrial rotors and focal sources in maintaining AF in diverse populations. Randomized trials of FIRM-guided ablation and mechanistic studies to determine how rotors form, progress, and regress are needed.

Natural History of Implantable Cardioverter-Defibrillator Implanted at or after the Age of 70 years in a Veteran Population: A Single Center Study.

BACKGROUND: The median age of patients in major Implantable Cardioverter-defibrillator (ICD)trials (MUSTT, MADIT-I, MADIT-II, and SCD-HeFT) was 63-67 years; with only 11% ≥70 years. There is little follow-up data on patients over 70 years of age who received an ICD for primary/secondary prevention of sudden cardiac death, particularly for veterans. OBJECTIVE: The aim of this study was to study the natural history of ICD implantation for veterans over 70 years of age. METHODS: We retrospectively reviewed single center ICD data in 216 patients with a mean age at implantation 76 ± 4 years. The ICD indication was primary prevention in 161 patients and secondary prevention in 55 patients. The ICD indication was unavailable in 4 patients. RESULTS: Mean duration of follow up was 1686 ± 1244 days during which 114 (52%) patients died. Of these, 31% died without receiving any appropriate ICD therapy. Overall, 60/216 (28%) received appropriate therapy and 28/216 (13%) received inappropriate therapy. Patients who had ICD implantation for secondary prophylaxis had statistically more (p= 0.02) appropriate therapies compared to patients who had ICD implantation for primary prevention. Indication for implantation and hypertension predicted appropriate therapy, while age at the time of implantation and presence of atrial fibrillation predicted inappropriate therapies. Overall, 7.7% had device related complications. CONCLUSIONS: Although 28% septuagenarians in this study received appropriate ICD therapy, they had high rates of mortality, inappropriate therapy, and device complications. ICD implantation in the elderly merits individualized consideration, with higher benefit for secondary prevention.

Pre-procedural Elevated White Blood Cell Count and Neutrophil-Lymphocyte (N/L) Ratio are Predictors of Ventricular Arrhythmias During Percutaneous Coronary Intervention.

AIMS: The absolute white blood cell (WBC) count and neutrophil to lymphocyte (N/L) ratio are predictors of death/myocardial infarction in patients who have undergone coronary angiography. We hypothesized that a pre-procedural elevated WBC count and an elevated N/L ratio would be a predictor of development of significant ventricular arrhythmias in subjects undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: We retrieved the data for all patients developing ventricular arrhythmia during PCI between 1999 to 2009 from our cath lab database (from 30,798 records), a total of 70 patients (Group I), and tabulated their WBC counts and absolute neutrophil and lymphocyte counts as well as N/L ratios. We compared the data with a random group of age, gender, medications and pre-existing condition matched controls (n=70) (Group II). We also adjusted for amount of myocardium under jeopardy. Group I had a significantly higher total WBC count (means 14,344 Vs 6852; 95% CI; p=0.0004); neutrophil count (means 75.79% Vs 58.06%; 95% CI; p < 0.0001) and N/L ratio (means 3.79 Vs 1.56; 95% CI; p < 0.0001) [means compared with t test]. CONCLUSION: Our data suggests a pre-procedural elevated WBC count, neutrophils and elevated N/L ratio are predictors of significant ventricular arrhythmias in patients undergoing percutaneous coronary intervention (PCI).