Role of myocardial bridging in the apical localization of stress cardiomyopathy

Myocardial bridging presenting as myocardial ischaemia induced cardiac arrest: a case report

Background

Myocardial bridging is a congenital anomaly defined as a segment of epicardial coronary arteries running through the myocardium. Various complications related to myocardial bridging have been reported, but at present, cardiac arrest has rarely been reported.

Case presentation

We report one case of a patient who was successfully resuscitated from ventricular fibrillation cardiac arrest and was diagnosed with myocardial bridging accompanied by myocardial ischaemia. A 50-year-old woman who had been resuscitated from cardiac arrest transferred to our institution for evaluation and management of out-of-hospital cardiac arrest. We confirmed the diagnosis of significant myocardial bridging with evident myocardial ischaemia by coronary angiography, resting echocardiography and heart MRI. Vasospasm was thought to be a trigger factor judging from the transient ST elevation on electrocardiography. In addition, the finding of septal buckling was detected for the first time throughout the whole cardiac cycle by resting echocardiography in MB.

Conclusion

We report a rare case of survival after out-of-hospital cardiac arrest that might be caused by significant myocardial bridging-induced myocardial ischaemia, which was objectively confirmed by echocardiography and heart MRI. Although myocardial bridging is often overlooked as an aetiology for sudden cardiac death, this case highlights the importance of expanding the differential diagnosis to myocardial bridging in the work-up for the cause of sudden cardiac death.

Bridging the Gap in a Rare Cause of Angina

Myocardial bridging occurs when coronary arteries run intramurally. Episodes of tachycardia can cause a dynamic obstruction that extends into diastole, compromising coronary filling time, and subsequently leading to ischaemia. Myocardial ischaemia, acute coronary syndrome, coronary spasm, myocardial stunning, arrhythmia, takotsubo cardiomyopathy, and sudden cardiac death have all been reported with bridging. Atherosclerotic plaques develop proximally in the bridge due to low shear stress and high oscillatory wall-flow. Factors affecting atherosclerotic build-up include disrupted flow patterns (particularly flow recirculation, which exacerbates LDL internalisation), cell adhesion and monocyte adhesion to the endothelium. Endothelial health depends on arterial flow patterns, given that the vessel reacts differently to various flow types, as confirmed in 3D simulations. Medication is the first-line therapy, while surgical de-roofing and coronary bypass are reserved for severe stenosis. Distinguishing physiological arterial compression from pathological stenosis is essential. Deeper bridges correlating with recurrent angina with an instantaneous wave-free ratio ≤0.89 or fractional flow reserve ≤0.80 are treated.

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.

Impact of myocardial bridging on in-hospital outcome in patients with takotsubo syndrome

BACKGROUND

Prevalence of myocardial bridging of the left anterior descending coronary artery (LAD) in patients with takotsubo syndrome (TTS) has been demonstrated. However, the impact of myocardial bridging on in-hospital outcome has not been fully evaluated.

METHODS

A total of 144 consecutive patients with TTS were enrolled. Coronary angiography and left ventriculography were performed in all patients and absence of obstructive coronary disease explaining the left ventricular contraction abnormality was confirmed. Myocardial bridging was diagnosed when a dynamic compression in systole, so-called "milking effect", was observed in the LAD. We evaluated differences in the clinical characteristics and in-hospital outcome between patients with and without myocardial bridging. Furthermore, multiple logistic regression analysis was performed to predict in-hospital death.

RESULTS

Myocardial bridging was observed in 33 patients (23%). In-hospital death was more frequent in patients with myocardial bridging (21% vs. 6%, p=0.02), which was due mainly to a higher non-cardiac death in those patients (15% vs. 5%, p=0.049). Multiple logistic regression analysis demonstrated myocardial bridging (odds ratio=12.0, 95% CI=2.52-78.5, p<0.01) as one of the independent predictors of in-hospital death.

CONCLUSION

Myocardial bridging is an independent predictor of in-hospital death in patients with TTS.

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.

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.

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

A woman presented with chest pain following emotional stress. Investigations showed acute ST-segment elevation, myocardial infarction, and elevated serum troponin. Emergency heart catheterization showed left anterior descending artery myocardial bridging, apical ballooning consistent with takotsubo cardiomyopathy (TTC), and decreased ejection fraction. Two days later, echocardiogram demonstrated near normalization of ventricular function.The etiology of TTC is not known but may include a stress-related surge of catecholamines or epicardial coronary spasm. Other case series reported an association of myocardial bridge and TTC. Catecholamines surge during stress might contribute to both diseases resulting in an apparent association; alternatively, a symptomatic myocardial bridge may be a contributing factor in worsening TTC.

Clinical characteristics of tako-tsubo cardiomyopathy

Tako-tsubo cardiomyopathy (TTC) is increasingly diagnosed in the United States, especially in the Caucasian population. To evaluate the clinical features and outcome of patients with TTC, we evaluated 34 patients (32 women and 2 men) 22 to 88 years of age (mean 66 +/- 14) who fulfilled the following criteria: (1) akinesia or dyskinesia of the apical and/or midventricular segments of the left ventricle with regional wall motion abnormalities that extended beyond the distribution of a single epicardial vessel and (2) absence of obstructive coronary artery disease. Twenty-five patients (74%) presented with chest pain, 20 patients (59%) presented with dyspnea, and 8 patients (24%) presented with cardiogenic shock. Twenty-two patients (65%) had ST-segment elevation and 14 patients (41%) had T-wave inversion on presentation. Twenty-five patients (74%) reported a preceding stressful event. Cardiac biomarkers were often mildly increased, with a mean troponin I (peak) of 13.9 +/- 24. Mean +/- SD left ventricular ejection fractions were 28 +/- 10% at time of presentation and 51 +/- 14 at time of follow-up (p <0.0001). Two patients (6%) died during the hospital stay. Average duration of hospital stay was 6.6 +/- 6.2 days. In conclusion, TTC is common in postmenopausal women with preceding physical or emotional stress. It predominantly involves the apical portion of the left ventricle and patients with this condition have a favorable outcome with appropriate medical management. The precise cause remains unclear.

Takotsubo cardiomyopathy or transient left ventricular apical ballooning syndrome: A systematic review

BACKGROUND

Transient left ventricular apical ballooning syndrome (TLVABS) is an acute cardiac syndrome mimicking ST-segment elevation myocardial infarction characterized by transient wall-motion abnormalities involving apical and mid-portions of the left ventricle in the absence of significant obstructive coronary disease.

METHODS

Searching the MEDLINE database 28 case series met the eligibility criteria and were summarized in a narrative synthesis of the demographic characteristics, clinical features and pathophysiological mechanisms.

RESULTS

TLVABS is observed in 0.7-2.5% of patients with suspected ACS, affects women in 90.7% (95% CI: 88.2-93.2%) with a mean age ranging from 62 to 76 years and most commonly presents with chest pain (83.4%, 95% CI: 80.0-86.7%) and dyspnea (20.4%, 95% CI: 16.3-24.5%) following an emotionally or physically stressful event. ECG on admission shows ST-segment elevations in 71.1% (95% CI: 67.2-75.1%) and is accompanied by usually mild elevations of Troponins in 85.0% (95% CI: 80.8-89.1%). Despite dramatic clinical presentation and substantial risk of heart failure, cardiogenic shock and arrhythmias, LVEF improved from 20-49.9% to 59-76% within a mean time of 7-37 days with an in-hospital mortality rate of 1.7% (95% CI: 0.5-2.8%), complete recovery in 95.9% (95% CI: 93.8-98.1%) and rare recurrence. The underlying etiology is thought to be based on an exaggerated sympathetic stimulation.

CONCLUSION

TLVABS is a considerable differential diagnosis in ACS, especially in postmenopausal women with a preceding stressful event. Data on longterm follow-up is pending and further studies will be necessary to clarify the etiology and reach consensus in acute and longterm management of TLVABS.