ROUTINE TRANSESOPHAGEAL ECHO PRIOR TO ATRIAL FIBRILLATION/FLUTTER ABLATIONS IN LOW RISK PATIENTS - ARE THEY NECESSARY?

Abstract

BACKGROUND: The physiopathology and determinants of high altitude pulmonary edema (HAPE) remain ill defined, but increased hypoxia-related pre-capillary pulmonary artery pressure (PAP) has been shown as a key component. No parameter has been validated to predict the development of HAPE among recreational climbers. We aimed to assess whether baseline right ventricular (RV) echocardiographic indices were predictive of an increased hypoxic PAP response. METHODS: 14healthy lowlander subjects (8men; ages 27-65 years old) were assessed by echocardiography at sea level (Montreal) and at 3450m (Namche Bazaar) and 4730m (Chukkung) during an expedition in the Khumbu Valley, Nepal. Baseline RV performance parameterswere analysed and compared to the systolic PAP maximal increment observed at high altitude; correlation coefficient (r) and coefficient of determination (r2) were calculated. RESULTS: At high altitude, none of the subjects had clinical criteria for HAPE, although all except one had ultrasound signs of interstitial lung water. Systolic PAP increased in all subjects between Montreal and Chukkung (mean PAP 27.4 +/5.4 mmHg vs. 39.3 +/7.7mmHg respectively; p<0.001). Sea level RV Tei index assessed by tissue doppler was moderately correlated to the PAP increment (r21⁄4 0.37), as was the s’ velocity at the tricuspid annulus (r2 1⁄4 0.27). Baseline Tricuspid Annular Plane Systolic Excursion (TAPSE) was strongly correlated to the PAP increment (fig. 1). The tricuspid E/e’ showed no correlation with PAP altitude-induced increment. RV free wall longitudinal strain was assessed and, although baseline value did not correlate with PAP increment (r21⁄4 0.05), strain increment betweenMontreal and Chukkung was moderately correlated to the PAP reached at the highest altitude (r2 1⁄4 0.39). CONCLUSION: RV echocardiographic indices such as TAPSE, s’ and Tei index at sea level correlate to the level at which PAP increases in lowlanders after a sub-acute ascent to high altitude. These findings reinforce the role of RV function in the development of high altitude pulmonary diseases and, should they be confirmed on a larger population, suggest that these indices could help counsel lowlanders before attempting high-altitude climbs. 315 ROUTINE TRANSESOPHAGEAL ECHO PRIOR TO ATRIAL FIBRILLATION/FLUTTER ABLATIONS IN LOW RISK PATIENTS ARE THEY NECESSARY?