Left Main Chronic Total Occlusion Percutaneous Coronary Intervention: A Case Series
BACKGROUND:Left main coronary artery (LMCA) chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS:We reviewed 4436 CTO-PCIs performed in 4340 patients between 2012 and 2018 at 25 sites. LMCA-CTO-PCI was performed in 20 cases (0.45%). We examined the clinical and angiographic characteristics and procedural outcomes of these cases. RESULTS:Mean patient age was 68 Â± 11 years and 65% were men. Most patients (85%) had undergone prior coronary artery bypass graft surgery and had a protected left main. Mean J-CTO score was 2.7 Â± 1.3, mean PROGRESS-CTO score was 1.3 Â± 1.1, and mean PROGRESS-CTO Complications score was 3.8 Â± 1.9. Antegrade-wire escalation was the most common successful crossing strategy (50%), followed by retrograde crossing (30%) and antegrade dissection/re-entry (10%). Technical and procedural success rates were both 85%. One patient with failed LMCA-CTO-PCI had periprocedural myocardial infarction. Median procedure time was 178 minutes (interquartile range [IQR], 123-250 minutes), median contrast volume was 190 mL (IQR, 133-339 mL), and patient air kerma radiation dose was 2.6 Gray (IQR, 1.3-3.9 Gray). CONCLUSIONS:LMCA-CTO-PCI is infrequent, is performed mostly in patients with prior coronary artery bypass graft surgery, and is associated with good procedural outcomes.
Change in P wave morphology after convergent atrial fibrillation ablation
Convergent atrial fibrillation ablation involves extensive epicardial as well as endocardial ablation of the left atrium. We examined whether it changes the morphology of the surface P wave. We reviewed electrocardiograms of 29 patients who underwent convergent ablation for atrial fibrillation. In leads V1, II and III, we measured P wave duration, area and amplitude before ablation, and at 1, 3 and 6 months from ablation. After ablation, there were no significant changes in P wave amplitude, area, or duration in leads II and III. There was a significant reduction in the area of the terminal negative deflection of the P wave in V1 from 0.38 mm(2) to 0.13 mm(2) (p = 0.03). There is also an acute increase in the amplitude and duration of the positive component of the P wave in V1 followed by a reduction in both by 6 months. Before ablation, 62.5% of the patients had biphasic P waves in V1. In 6 months, only 39.2% of them had biphasic P waves. Hybrid ablation causes a reduction of the terminal negative deflection of the P wave in V1 as well as temporal changes in the duration and amplitude of the positive component of the P wave in V1. This likely reflects the reduced electrical contribution of the posterior left atrium after ablation as well as anatomical and autonomic remodeling. Recognition of this altered sinus P wave morphology is useful in the diagnosis of atrial arrhythmias in this patient population.