Aims Mahaim‐type accessory pathways (MAPs) are generally right‐sided due to the embryological differentiation, but left‐sided localization is also possible. This study aims to compare the clinical and electrophysiological characteristics of right‐ and left‐sided MAPs. Methods Of 251 patients diagnosed with AP by electrophysiological study between November 2015 and February 2020, 12 patients with MAP were included (right sided n = 8, left sided n = 4). MAP was diagnosed if; (1) no retrograde conduction; (2) anterograde decremental conduction; (3) adenosine sensitivity; and (4) Mahaim potential at successful ablation site were present. Results Ten of twelve MAPs were clustered on the lateral walls of the mitral (n = 3, 75%) and tricuspid annuli (n = 7, 87.5%). Right‐sided MAPs were mostly long pathways extending toward the conduction system whereas left‐sided MAPs were short extending toward the neighboring myocardium. For right‐ and left‐sided APs, the median QRS times were 129 and 156 ms (p = .042), the median VAbl‐RVApex intervals were −12 and 64 ms (p = .007), the median QRS‐V(His) intervals were 16 and 86 ms (p = .120), and the median VAbl‐QRS interval was −8 and 12 ms (p = .017), respectively. Coexistence of dual atrioventricular node physiology was observed only in right‐sided APs (n = 3, 37.5%). Conclusion MAPs are more typically located on the right but may rarely be seen on the left. Catheter ablation was associated with high success without complications.

Background Supervised high-intensity interval training (HIIT) has been proposed to be more effective than moderateintensity continuous training (MICT) for improving exercise capacity, but there are not sufficient information effects of home-based HIIT and MICT in patients with myocardial infarction (MI). Aims To compare the effects of home-based HIIT and MICT in patients with MI. Methods Twenty-one patients with MI were randomly assigned to one of two home-based exercise modes: HIIT group and MICT group. Home-based HIIT and MICT were performed twice a week for 12 weeks with an exercise intensity of 85-95% of heart rate (HR) reserve and 70-75% HR reserve, respectively. The primary outcome measure was functional capacity. Secondary outcomes included resting blood pressure and HR, peripheral oxygen saturation, pulmonary function and respiratory muscle strength, dyspnea severity, body composition (body fat%, body mass ındex (BMI), fat free muscle), peripheral muscle strength, and health-related quality of life (HRQoL). Results Functional capacity, measured by 6-minute walk test, increased in HIIT and MICT group (p < 0.05). Resting BP and HR, body fat%, and BMI were significantly decreased, and pulmonary functions, respiratory-peripheral muscle strength, and HRQoL were significantly increased in the both groups (p < 0.05). Home-based HIIT was more effective than MICT in improving pulmonary functions and lower extremity muscle strength (p < 0.05). Conclusions This study suggests that HIIT and MICT can be applied at home-based in patients with MI and play an important role in improving functional capacity, health outcomes, and HRQoL. Trial registration Clinical Trials Number: NCT04407624.

Upper venous system anatomic variations may cause difficulties during cardiac pacemaker implantation. Persistent left superior vena cava (PLSVC) and absent right superior vena cava could be an arrhythmogenic source of atrial arrhythmias and cardiac conduction disease. We represent dual-chamber pacemaker implantation in a patient with a very rare upper venous system anomaly, paroxysmal atrial fibrillation, sick sinus syndrome, that cause unusual fluoroscopic image.

ST‐elevation myocardial infarction (STEMI) is a life‐threatening clinical condition that requires immediate intervention, mostly caused by complete occlusion of epicardial vessels. Other diseases such as myocarditis, pericarditis, electrolyte disturbance, and early repolarization may mimic. We present a rare case of atrial lead‐related atrial perforation which mimics inferior STEMI.

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