Atrial tachycardia in a patient with severe pectus excavatum

Abstract

A 68-year-old woman underwent catheter ablation of drug-refractory atrial tachycardia (AT; cycle length 490 ms). A computed tomography scan of her chest showed severe pectus excavatum (PEX) (Figure 1A ). A voltage map using a multipolar high-density mapping catheter with the EnSite X mapping system (Abbott Technologies, Minneapolis, MN) revealed severe distortion of the right atrium (RA) and an extensive low-voltage area (LVA; <0.5 mV), which occupied 32% of the RA surface (Figure 1B). The AT demonstrated a centrifugal activation pattern arising at the inferior portion of the cavotricuspid isthmus (Online Supplemental Video 1), and the AT was eliminated by ablation at the earliest activation site on the LVA. In PEX, distortion of the right heart cavities can cause traction on the myocardial wall resulting in wall thinning. 1 Oezcan S. Attenhofer Jost C.H. Pfyffer M. et al. Pectus excavatum: echocardiography and cardiac MRI reveal frequent pericardial effusion and right-sided heart anomalies. Eur Heart J Cardiovasc Imaging. 2012; 13: 673-679 Crossref PubMed Scopus (44) Google Scholar In the present case, an extensive LVA was found in the area apart from the RA free wall and thus in the lower part of the RA and in the entire peri-tricuspid annulus, where more tractions can exert than normal and may result in wall thinning (Figure 1B). This makes it likely that the mechanism of the AT was either abnormal automaticity or microreentry caused by damage to the RA by severe PEX. This report adhered to CARE case report guidelines (https://www.care-statement.org/).