AV-optimized conduction system pacing for treatment of AV dromotropathy: A randomized, cross-over study.

BACKGROUND: Severe first-degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce. OBJECTIVES: This study aimed to determine the impact of AV-optimized conduction system pacing (CSP) in patients with symptomatic severe first-degree AV block and echocardiographic signs of AV dyssynchrony. METHODS: Patients with symptomatic first-degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single-blind cross-over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period. RESULTS: Fourteen patients completed the study. During the AV-optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV-optimized CSP (p = .008). CONCLUSIONS: AV-optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first-degree AV block.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

AIMS: Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. METHODS AND RESULTS: The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). CONCLUSION: Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Diagnostic yield of implantable loop recorders in patients with unexplained syncope: single-center experience.

BACKGROUND: A significant proportion of patients have syncope of uncertain etiology. While implantable loop recorder (ILR) has become an important diagnostic tool in diagnosing syncope, its contemporary role in accordance with the recently updated syncope guidelines is not well established. The purpose of this single-center retrospective study was to determine the diagnostic yield of ILR in patients with unexplained syncope following initial diagnostic work-up as recommended by the guidelines. METHODS: Medical records of 100 consecutive patients with syncope or presyncope who received ILR following the recently updated recommended diagnostic work-up were retrospectively evaluated. RESULTS: Seven patients were lost to follow-up (7%). During a median follow-up of 12 months (IQR 6.5-27.5), syncope or presyncope recurred in 61 patients (65.6%). In 37 (37/61, 60.7%), correlation between abnormal heart rhythm and symptoms was confirmed by ILR. Syncope was predominantly caused by bradyarrhythmia (33/37, 89.2%). Of the remaining four patients, three (8.1%) had ventricular tachycardia and one had atrial fibrillation with rapid ventricular response. Arrhythmogenic cause of syncope or presyncope was excluded in 24 patients (24/61, 39.3%) as no arrhythmia was recorded at the time of reported symptoms. Median time to establishing diagnosis was 354 days (171-783). CONCLUSIONS: The diagnostic yield of ILR after initial inconclusive recommended diagnostic work-up in accordance with the relevant guidelines was high. The findings affirm ILR as an important diagnostic tool in contemporary management of syncope.

Multicentric Atrial Strain COmparison between Two Different Modalities: MASCOT HIT Study.

Two methods are currently available for left atrial (LA) strain measurement by speckle tracking echocardiography, with two different reference timings for starting the analysis: QRS (QRS-LASr) and P wave (P-LASr). The aim of MASCOT HIT study was to define which of the two was more reproducible, more feasible, and less time consuming. In 26 expert centers, LA strain was analyzed by two different echocardiographers (young vs senior) in a blinded fashion. The study population included: healthy subjects, patients with arterial hypertension or aortic stenosis (LA pressure overload, group 2) and patients with mitral regurgitation or heart failure (LA volume-pressure overload, group 3). Difference between the inter-correlation coefficient (ICC) by the two echocardiographers using the two techniques, feasibility and analysis time of both methods were analyzed. A total of 938 subjects were included: 309 controls, 333 patients in group 2, and 296 patients in group 3. The ICC was comparable between QRS-LASr (0.93) and P-LASr (0.90). The young echocardiographers calculated QRS-LASr in 90% of cases, the expert ones in 95%. The feasibility of P-LASr was 85% by young echocardiographers and 88% by senior ones. QRS-LASr young median time was 110 s (interquartile range, IR, 78-149) vs senior 110 s (IR 78-155); for P-LASr, 120 s (IR 80-165) and 120 s (IR 90-161), respectively. LA strain was feasible in the majority of patients with similar reproducibility for both methods. QRS complex guaranteed a slightly higher feasibility and a lower time wasting compared to the use of P wave as the reference.

Accidental cannabis poisoning in the elderly.

There are two main varieties of Cannabis sativa plant, namely, hemp which is cultivated for fiber and seeds and contains low amounts of psychoactive cannabinoids and the other which is cultivated for the drug cannabis or marijuana. Increasing popularity of hemp food products and alleged beneficial effects of cannabinoids in the drug variety of cannabis might lead to confusion in the lay population and unintentional ingestion of marijuana, as described in this case report. During a workshop on the use of hemp for medicinal purposes, there was a degustation of various hemp food products including also cookies that were brought by one of the attendees. Approximately 1 h after ingestion of cookies, people experienced nausea and vomiting, dizziness, sleepiness and difficulty walking. Twelve people were referred to emergency department, where two were admitted to intensive care because of central nervous system depression. They were all managed with supportive measures and were discharged home without health-related consequences.