Left Atrial Dissection after Mitral Valve Replacement Demonstrated by Transesophageal Echocardiography

Left atrial dissection is one of extremely rare complications associated with mitral valve surgery. We reported a case of left atrial dissection, which was developed after mechanical mitral valve replacement and was demonstrated by transesophargeal echocardiography. The cause of dissection was due to excessive traction of left atrial endocardial layer during surgery.

Adenosine Triphosphate Stress Echocardiography

BACKGROUND: Stress echocardiography have been emerged as an important non-invasive diagnostic tool to detect coronary artery disease. Previous studies indicated that adenosine triphosphate(ATP) is a potent coronary vasodilator as adenosine, the time of action onset and half-life is shorter than dipyridamole, the duration of adverse effect is transient and the use of aminophylline is not needed when side effects develop. The purpose of this study was to evaluate the feasibility and diagnostic accuracy of ATP stress echocardiography in patient with suspected coronary artery disease. METHOD: We investigated 20 patients(mean age 56+/-11, male 11, female 9) who underwent stress echocardiography with ATP infusion(0.15 mg/kg/min for 4 min) and quantitative coronary angiography(QCA). The digitized echocardiographic images were analyzed using wall motion score(1: normal, 2: hypokinesia, 3: akinesia, 4: dyskinesia) in 16 segments. Positivity of ATP stress echocardiography was based on the detection of transient regional wall motion abnormality. The hemodynamic changes and occurrence of adverse effects was carefully monitored. RESULTS: Forteen out of 20 patients had coronary artery disease(>50% diameter stenosis by QCA). Nine out of 14 patients had transient regional wall motion abnormality at coronary artery disease territory(sensitivity 64%). The mean wall motion score index in patients mth positive test was 1.01+0.01 at base and 1.20+0.08 during ATP infusion(p<0.05). Six out of 20 patients who had no regional wall motion abnormality had no coronary artery disease (specificity 100%) with overall diagnostic accuracy of 75%. ATP stress echocardiography showed good agreernent with QCA(kappa value 0.52). Side effect profile revealed chest pain in 6 patients(30%), facial flushing in 3 patients(15%), Wenchebach type AV block in 2 patients(10%) and significant ST-segrnent depression in 1 patients(5%). The mean heart rate, mean systolic and diastolic blood pressure, and mean rate-pressure product were not changed significantly. CONCLUSION: ATP stress echocardiography is feasible and has a diagnostic value similar to that of adenosine and dipyridamole for detecting coronary artery disease with low cost. In addition, it may have minimal side effects and insignificant clinical consequences.