Takotsubo syndrome with transient complete atrioventricular block

Takotsubo syndrome (transient left ventricular apical ballooning syndrome) is a novel cardiac syndrome of left ventricular apical ballooning involving reversible left ventricular apical ballooning (during systole) of acute onset with chest pain, electrocardiographic changes, and minimal elevation of cardiac enzymes resembling acute myocardial infarction, but without evidence of myocardial ischemia or injury. Patients have no angiographic evidence of coronary artery stenosis and there is almost always a complete recovery of left ventricular function in days to weeks. The precise etiologic basic of this syndrome is not clear but most likely it is a non-ischemic, metabolic syndrome caused by stress-induced activation of the cardiac adrenoceptors in absence of ischemia and reperfusion.1-3 Reported here is a case of stress-induced transient left ventricular apical ballooning syndrome in an elderly Chinese woman. CASE REPORT A 72 years old Chinese ex-smoked woman without any significant medical history was presented with recurrent onsets of typical angina for 3 days, which occurred severely in the morning, July 4, 2005 in which she was admitted. She was treated with sublingual nitroglycerin spray, morphine intraveneously and a metoprolol per oral, and had complete resolution of symptoms. Physical examination was unremarkable. Initial electrocardiogram revealed Wenckebach AV block with complete RBBB, ST elevation in leads V2-V6, Q wave in leads II, III, avF with corrected QT interval of 0.42 seconds (Fig. 1). Repeat electrocardiogram for few hours showed complete AV block and RBBB, the elevation of ST tend back to baseline with flat or slight inversion of T-wave in lead V2-V6 (Fig. 2).Then the patient received temporary pacing right ventricle therapy. Emergency coronary angiogram showed minor regularity of distal left anterior descending artery and normal other coronary arteries like the coronary angiogram finding 6 years ago (Fig. 3). Left ventriculography confirmed the apical hypokinesia of echocardiographic finding, left ventricular ejection fraction was 42% (Fig. 4). The serum type MB cardiac kinase concentration was only slightly elevated with peaks of 51 U/ml and troponin I concentration was 7.39 ng/ml at admitted. Echocardiography has done after 24 hours of admission revealed hypokinesis of anterior septum with left ventricular ejection fraction of 46%, moderate mitral and tricuspid valve regurgitation and slight high right ventricular systolic pressure of 31.8 mmHg.Fig. 1.: Initial electrocardiogram shows Wenckebach AV block with complete RBBB, elevation of pericardial ST segment with QS wave in lead II, III, avF. QTc interval is 420 ms.Fig. 2.: Repeat electrocardiogram few hours shows IIIo AV block with complete RBBB, elevation of pericardial ST segment tend back to baseline with initial minor r wave in lead II, III, avF.Fig. 3.: Emergency coronary angiogram shows minor regularity of distal left anterior decending artery and normal other coronary arteries.Fig. 4.: Left ventriculography demonstrates akinesia of distal anterior, apical, and basal regions of left ventricle with hypercontraction of the basal segment. (A) Systole; (B) diastole.Patient was continued on aspirin, metoprolol. After two days of admission, electrocardiogram showed sinus rhythm, normal presentation of ST-T waves and appearance of minor initial r-wave in leads II, III, avF (Fig. 5). The systolic function gradually improved and a transthoracic echocardiography A repeat echocardiography showed normalization of the regional contractility with ejection fraction of 50% at day 7. The patient was discharged on aspirin, metoprolol and ramipril peroral.Fig. 5.: Electrocardiogram shows sinus rhythm, flat and slight inversion of ST-T waves in pericardial lead and appearance of minor initial r-wave in leads II, III, avF 4 days after admission.DISCUSSION Takotsubo syndrome, another called of transient left ventricular apical ballooning syndrome is a syndrome presenting a reversible unique balloon-like left ventricular wall motion abnormality, characterized as a reversible balloon-like left ventricular wall motion abnormality at the apex with hypercontraction of the basal segment, and acute myocardial infarction on ECG without significant stenosis on coronary angiography. This entity was introduced as “tako-tsubo-like left ventricular dysfunction” in 1990 by Satoh and colleagues, and several reports have followed in Japan.1 “Tako-tsubo” is a fishing pot with a round bottom and narrow neck, which is used for trapping octopuses in Japan. Apical ballooning is often associated with a physical or emotional stress factor, chest pain, and only a limited release of cardiac markers.2 The syndrome has been described in Japanese and white patients which has been reported case number amount of 180 approximately, most of whom are women.2-6 There are even no an incidence survey had been taken based on the regional population. The clinical diagnostic criteria were reported by Abe and colleagues firstly,7 and then developed to the proposed Mayo criteria which including all 4 issues must be met.2 1) Transient akinesis or dyskinesis of the left ventricular apical and mid-ventricular segments with regional wall-motion abnormalities extending beyond a single epicardial vascular distribution; 2) Absence of obstructive coronary disease or angiographic evidence of acute plaque rupture; 3) New electrocardiographic abnormalities (either ST-segment elevation or T-wave inversion); 4) absence of recent significant head trauma, intracranial bleeding, pheochromocytoma, obstructive epicardial coronary artery disease, myocarditis and hypertrophic cardiomyopathy. Various pathophysiological mechanisms have been hypothesized such as multiple vasospastic angina, catecholamine-mediated myocardial stunning and enhanced sympathetic activity secondary to internal (emotional) and external stresses (trauma, surgical procedure, etc).2-8 However, establishment of its name, etiology, criteria, management, and outcome remain challenging tasks. Studies have indicated that triggering factors such as emotional exposure and physical stress may play a pivotal role in the pathophysiological basis of this condition. 2-4,9 Therefore, this syndrome might be one of the clinical models of the stress-related sudden death. Awareness of this syndrome is important because it mimics acute myocardial infarction and may inadvertently expose patients to a futile administration of thrombolytic agents or a futile attempt of coronary intervention. In the absence of critical coronary arterial disease, the diagnosis of takotsubo syndrome should be considered when the history taking reveals that cardiac symptoms were precipitated by intense emotional stress, when there is a unique pattern of left ventricular dysfunction characterized by apical and mid-ventricular contractile abnormalities with sparing of the basal segments, and when there is minimal elevation of cardiac enzymes despite the presence of large regions of focal akinesis in the myocardium. The clinical diagnosis is reinforced by the development of elevation of ST segment or deep precordial or global T-wave inversion, in some cases with markedly prolonged QT interval on electrocardiography during the first 48 hours in the hospital, as well as rapidly improving cardiac contractility on serial echocardiography. In this case, clinical characteristics satisfied the diagnosis criteria of proposed Mayo. The transient heart block which combined with takotsubo cardiomyopathy had not even been reported. Since there have not critical lesion be seen in coronary artery angiogram, which can induce, it seems not likely associated with perfusion insufficiency. Whether that have or not microvascular malfunction is unknown. The treatment of takotsubo syndrome or named also takotsubo cardiomyopathy, beyond standard supportive care for congestive heart failure with diuretics and vasodilators, remains largely empirical. When medical support is provided initially, patients with stress cardiomyopathy have rapid clinical and echocardiographic improvement and have an excellent prognosis. In a four years follow-up study, there had no patients had died, recurrence or decline in left ventricular function.6 Since there no Chinese case has been reported before, the occurrence of this syndrome as we presented may point to a further etiological investigation in Chinese.