Association of myocardial bridge and Takotsubo cardiomyopathy: a case report and literature review

Mid-ventricular Takotsubo Cardiomyopathy With Coexisting Myocardial Bridge

Typical takotsubo cardiomyopathy (TCM) is a reversible form of myocardial injury that presents with a characteristic ballooning abnormality of the left ventricular apex. Typical TCM has been associated with myocardial bridging; however, mid-ventricular variant TCM has not. We describe a rare case of mid-ventricular variant TCM with a coexisting left anterior descending artery myocardial bridge and discuss management strategies. Furthermore, we propose potential pathophysiological mechanisms that may contribute to the symptomatic presentation of both conditions as a manifestation of common etiological factors.

The Myocardial Bridge: Potential Influences on the Coronary Artery Vasculature

A myocardial bridge (MB) is an anatomical abnormality of the coronary artery and is characterized by the systolic narrowing of the epicardial coronary artery caused by myocardial compression during systole. An MB is frequently observed on cardiac computed tomography or coronary angiography and generally appears to be harmless in the majority of patients. However, the presence of MB is reportedly associated with abnormalities of the cardiovascular system, including coronary artery diseases, arrhythmia, certain types of cardiomyopathy, and cardiac death, indicating that MB serves a pivotal role in the occurrence and/or development of such cardiovascular events. Recently, there has been an increasing interest in the coexistence of MB and coronary spasm in research due to opposing aspects regarding their treatments. For example, monotherapy using β-blockers, which are effective in patients with MB, may worsen symptoms in patients with coronary spasm. By contrast, nitroglycerin, which is an effective treatment option for coronary spasm, may worsen symptoms in patients with MB. This review focuses on the pathophysiology and diagnosis of MB and MB-related cardiovascular diseases, including coronary spasm, and on the treatment strategies for MB.

Three-vessel myocardial bridging: A possible cause of myocardial stunning

The authors report a rare clinical case of myocardial bridging of the three major coronary arteries, which manifested in an unusual way with severe biventricular dysfunction in the context of tachycardia. For the diagnosis, the authors relied on non-invasive multimodality cardiac imaging, including cardiac magnetic resonance, computed tomography angiography and myocardial perfusion scintigraphy. The implementation of targeted medical and neurohormonal therapy resulted in the recovery of ventricular function and clinical improvement.

A potential protective element of myocardial bridge against severe obstructive atherosclerosis in the whole coronary system

BACKGROUND

Myocardial bridge (MB) is generally described as a congenital benign variation. Previous studies have suggested that MB prevents atherosclerotic plaques from accumulating within the bridge segment but promotes coronary stenosis in the proximal segment adjacent to MB. However, it is still not clear whether MB has positive or negative effects on severe obstructive atherosclerosis in the whole coronary artery system.

METHODS

In this study, 6774 patients with symptoms of angina who were clinically diagnosed coronary artery disease (CAD) or suspected CAD underwent coronary angiography (CAG) in our center. The presence of MB was diagnosed, and a retrospective analysis was performed between MB and severe obstructive CAD requiring percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in the whole coronary system.

RESULTS

Among 6774 patients, 3583 (52.89%) were diagnosed with severe obstructive CAD (SOCAD) requiring a treatment of PCI or CABG and enrolled into the SOCAD group; and 3191 (47.11%) without SOCAD into the non-SOCAD group. Non-SOCAD and SOCAD groups had 512(16.05%) and 66(1.84%) patients with MB, respectively (P <  0.0001). The rate of SOCAD requiring PCI or CABG in patients with MB was much lower than that in patients without MB (11.42% vs. 56.76%, P <  0.0001). After adjusting for sex, age, diabetes mellitus, hypertension, and other risk factors, MB still had some positive role in preventing severe obstructive CAD (log-OR = - 2.134, p-value < 0.0001) through logistic regression.

CONCLUSIONS

Our results provided a clue that MB might act as a potential protective element against severe obstructive atherosclerosis in the whole coronary artery system.

Takotsubo Cardiomyopathy Coexisting with Acute Pericarditis and Myocardial Bridge

Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy that occurs primarily in postmenopausal women. It mimics clinical picture of acute coronary syndrome with nonobstructive coronary arteries and a characteristic transient left (or bi-) ventricular apical ballooning at angiography. The exact pathogenesis of TCM is not well recognized. Hereby we present an unusual case of TCM that presents with signs and symptoms of acute pericarditis and was also found to have a coexisting coronary muscle bridge on coronary angiography. We discuss the impact of these associations in better understanding of the pathogenesis of TCM.

In-hospital and long-term mortality in Takotsubo cardiomyopathy: a community hospital experience

Background

Takotsubo cardiomyopathy (TTC) is characterized by reversible left ventricular dysfunction, frequently precipitated by a stressful event. Despite the favorable course and good long-term prognosis, a variety of complications may occur in the acute phase of the disease. The aim of this study was to evaluate the in-hospital and long-term outcomes of a cohort of TTC patients.

Methods

Fifty-five patients (mean age 68.1±12 years) were prospectively followed for a mean of 69.6±32.2 months (64,635 days). In-hospital (death, heart failure, arrhythmias) and long-term events (death and recurrences) were recorded.

Results

Patients were predominantly women (87.3%) who experienced a recent stressful event (emotional or physical) and were admitted to hospital for chest pain. Eleven patients (20%) had a diagnosis of depressive disorder, and arterial hypertension was the most frequent cardiovascular risk factor. The ECG revealed ST-segment elevation in 43.6% of patients. At angiography, seven cases (12.7%) had at least one significant (≥50%) coronary artery stenosis and four patients (7.3%) had myocardial bridging of the left anterior descending artery. During hospitalization, three patients died (one from cardiac causes) and cardiovascular complications occurred in 12 patients. During follow-up, five patients died (none from cardiac causes), six patients had recurrences within the first year. Two patients had two recurrences: one after 114 days, triggered by an asthma attack as the first event, and the other after 1,850 days.

Conclusions

In TTC patients, in-hospital and long-term mortality is primarily due to non-cardiovascular causes. Recurrences are not infrequent and coronary artery disease is not an uncommon finding.

Takotsubo cardiomyopathy as a sequela of elective direct-current cardioversion for atrial fibrillation

In takotsubo cardiomyopathy, the clinical appearance is that of an acute myocardial infarction in the absence of obstructive coronary artery disease, with apical ballooning of the left ventricle. The condition is usually precipitated by a stressful physical or psychological experience. The mechanism is unknown but is thought to be related to catecholamine excess. We present the case of a 67-year-old woman who experienced cardiogenic shock caused by takotsubo cardiomyopathy, immediately after undergoing elective direct-current cardio-version for atrial fibrillation. After a course complicated by left ventricular failure, cardiogenic shock, and ventricular tachycardia, she made a complete clinical and echocardiographic recovery. In addition to this case, we discuss the possible direct effect of cardioversion in takotsubo cardiomyopathy.

LAD coronary artery myocardial bridging and apical ballooning syndrome

OBJECTIVES

This study sought to evaluate the prevalence and potential role of myocardial bridging in the pathogenesis of apical ballooning syndrome (ABS).

BACKGROUND

ABS is characterized by reversible left ventricular dysfunction, frequently precipitated by a stressful event, but the pathogenesis remains still unclear.

METHODS

Forty-two consecutive patients (40 female, mean age 66 ± 7 years) with ABS underwent echocardiography, cardiac magnetic resonance, coronary angiography (CA) with intravascular ultrasound, and computed tomography angiography (CTA). Myocardial bridging was diagnosed by CA when a dynamic compression phenomenon was observed in the coronary artery and by CTA when a segment of coronary artery was completely (full encasement) or incompletely (partial encasement) surrounded by the myocardium. The prevalence of myocardial bridging detected by CTA and CA in ABS patients was compared with 401 controls without ABS who underwent both CTA and CA.

RESULTS

Myocardial bridging by CTA was observed in 32 ABS patients (76%): 23 with partial encasement and 9 with full encasement. All myocardial bridging was located in the mid segment of the left anterior descending coronary artery (LAD) with a mean length of 17 ± 9 mm. CA revealed myocardial bridging in 17 subjects (40%) (9 with partial encasement and 8 with full encasement by CTA). All subjects in which dynamic compression was observed by CA showed myocardial bridging by CTA, while none of the subjects with negative findings for myocardial bridging by CTA revealed dynamic compression by CA. Compared with controls, ABS patients showed a significant higher prevalence of myocardial bridging in the LAD either by CA (40% vs. 8%; p < 0.001) or by CTA (76% vs. 31%; p < 0.001).

CONCLUSIONS

Our study showed that myocardial bridging of the LAD is a frequent finding in ABS patients as revealed both by CA and, mostly, by CTA, suggesting a role of myocardial bridging as potential substrate in the pathogenesis of ABS.

Depression, stress, and heart disease in earthquakes and Takotsubo cardiomyopathy

The preponderance of evidence links depressive disorder and coronary heart disease (CHD). Despite this evidence, multiple clinical trials have failed to show that effective treatment of depression favorably modifies the development, clinical course, or outcome of comorbid CHD. Possible reasons for these failures include the heterogeneity of depression, limitations of assessment instruments, limited understanding of the biology of depressive disorders, lack of biological markers, and the observation that depression may be more a product of CHD than a true risk factor for it. In this commentary, to better address the effects of externally provoked stress on physical health, we examine evidence about 2 specific examples of stress and subsequent heart disease: earthquake-induced adverse cardiac events among individuals with coronary artery disease, and stress-induced Takotsubo cardiomyopathy. In the former case, existing studies suggest that the stress and distress of earthquakes accelerate the development of poor cardiac outcomes for individuals with established coronary artery disease. In the latter example, existing case studies indicate that the profound left ventricular dysfunction of Takotsubo cardiomyopathy tends to quickly normalize once the acute stress is relieved. Together, these examples indicate that the presence or absence of prestress medical illness and its severity may better determine the outcome of the medical illness than the nature and severity of the stress, including depression. That is, any effort to look at depression among individuals with medical illness must look carefully at the medical illness itself and consider depression a possible nonspecific stress. In patients with comorbid depression and CHD, we propose using the more firmly established CHD outcome measurements to better understand how depression or other stressors and their associated treatments influence the prognosis and outcome of this medical illness.