The atrial effective refractory period increases, sinus node function improves, and atrial conduction velocity goes up in the first week after cardioversion of long-standing atrial fibrillation in humans. Reverse electrical remodeling of the effective refractory period occurs at different rates in different regions of the atrium.

A 43-year-old female, admitted because of acute infero-posterior myocardial infarction, showed angiographic findings of 100%occlusion of left circumflex artery. Echocardiographic findings showedinferior hypokinesis, while a large left intraatrial tumor was also observed. The coronary angiography on the 17th hospital day showed complete reperfusion of the culprit lesion without stenosis. On the 21st hospital day, the removal operation of the tumor was performed. Pathological findings showed typical cardiac myxoma,and the etiology of the occlusion at the culprit vessel was presumed to be closely related to the existence of the left atrial tumor. (Internal Medicine 36: 31-34, 1997) Key words: coronary embolism, left atrial tumor, complete later reperfusion Case Report Wetreated a rare case of left atrial myxoma complicated with acute inferior and posterior myocardial infarction. A 43-year-old female was admitted to our emergency service 100 minutes after the onset of severe chest pain. Physical findings showed a height of 158 cm, weight of 54 kg, body temperature of 36.9°C, regular pulsation of 70/min, and blood pressure of 1 06/70 mmHg. She had no lymphadenopathy or pretibial edema.Auscultation showed systolic ejection murmurand diastolic rumble at the precordial apical portion, and normal vesicular sound with no rales. Abdomenwas soft and flat without any mass palpable. Laboratory findings showed a white blood cell count of 8,700/mm3, hemoglobin 1 1.0 mg/dl, hematocrit 36.8%, platelet 28.7xlO4/mm3, glutamic oxalacetic transaminase 2 1 1 U//, lactic dehydrogenase 348 IU//, creatinine phosphokinase 62 IU//, myoglobin 329 ng/dl, creatinine 0.8 mg/dl, sodium 142 mEq//, potassium 3.5 mEq//, chloride 107 mEq//. Analysis of arterial blood gas during 3 //rnin of pure oxygen gas supply revealed PO2 1 34 mmHg, PCO2 22mmHg, HCO3 23 mEq//. On electrocardiogram, a normal sinus rhythm with ST elevation at II, III, aVf leads, and ST depression with T wave inversion at V1-V4leads were observed. There was no abnormal finding on the chest X-ray picture. She was then diagnosed as having acute myocardial infarction of the inferior and posterior walls, and emergency coronary angiography was done immediately. The angiography demonstrated normal left anterior descending and right coronary artery, and complete occlusion of the left circumflex #1 3 (Fig. 1A). Intracoronary administration of tissue plasminogen activator (t-PA) failed to reperfuse the culprit lesion and the continuous infusion of heparin was started thereafter. On the echocardiogram, inferior hypokinesis of the left ventricular wall wasseen, while a large solid masswas observed inside the left atrium, and the mass was attached to the interatrial septum by a stalk (Fig. 2). The maximumvalue of creatinine phosphokinase was 744 IU//; the patient was free from any complication during the course. On the 17th hospital day, a cardiac catheterization examination was done. Central venous pressure was 6 mmHg, pulmonary capillary wedge pressure 14 mmHg,and the cardiac index 2. 1 /...

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I n chronic mitral regurgitation (MR), increased preload and reduced afterload due to unloading from the left ventricle (LV) into the left atrium (LA) leads to compensatory dilation of the LV and facilitates LV ejection. Although this response initially maintains cardiac output, myocardial decompensation eventually results in heart failure symptoms and an increased risk of sudden death. In addition, backflow into the LA results in enlargement of the LA, atrial fibrillation and elevated pulmonary pressures. In some patients, LV contractility is irreversibly impaired in the absence of symptoms (1-3). Thus, deferring surgical intervention often leads to irreversible postoperative LV dysfunction. Valve replacement or valvuloplasty is essential before the myocardial damage becomes irreversible.Early valvuloplasty conducted when heart failure is mild has been reported to improve prognosis (4). In clinical practice, however, it remains difficult to decide the timing of surgery defined by mild heart failure symptoms and preserved cardiac function.Some reports have shown that preoperative LV function (LV end-diastolic diameter [LVDd], LV end-systolic diameter BACKGROUND: Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels were characterized in subjects with mitral regurgitation (MR). METHODS: Sixty-two cases of moderate or severe chronic MR were studied. The blood levels of neurohormonal factors were stratified by the known MR prognostic factors of New York Heart Association (NYHA) functional class, left ventricular end-diastolic diameters, left ventricular end-systolic diameter (LVDs), ejection fraction (EF), left atrial diameter and presence of atrial fibrillation (AF). RESULTS: ANP levels were higher in NYHA class II and lower in classes I and III/IV (P=0.0206). BNP levels were higher in NYHA class II than class I (P=0.0355). The BNP/ANP ratio was significantly higher in NYHA classes II and III/IV than in class I (P=0.0007). To differentiate between NYHA classes I/II and III/IV, a cut-off BNP/ANP ratio of 2.97 produced a sensitivity of 78% and specificity of 87%. Compared with subjects in sinus rhythm, patients with AF had an enlarged left atrium and lower ANP levels. The BNP/ANP ratio correlated significantly with left atrial diameter, LVDs and EF (r=0.429, P=0.0017; r=0.351, P=0.0117; and r=-0.349, P=0.0122; respectively), and was significantly higher among all the known operative indications for MR tested (LVDs 45 mm or more, EF 60% or less, NYHA class II or greater and AF; P=0.0073, P=0.003, P=0.0102 and P=0.0149, respectively). CONCLUSIONS: In chronic MR, levels of ANP and BNP, and the BNP/ANP ratio are potential indicators of disease severity.

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