Increased responsiveness of left ventricular apical myocardium to adrenergic stimuli

Stress-induced cardiomyopathy

OBJECTIVES

Reversible stress-induced cardiac dysfunction is frequently seen as a complication of a multitude of acute stress states, in particular neurologic injuries. This dysfunction may be difficult to distinguish between that caused by myocardial ischemia and may impact both the treatment strategies and prognosis of the underlying condition. Critical care practitioners should have an understanding of the epidemiology, pathophysiology, clinical characteristics, precipitating conditions, differential diagnosis, and proposed treatments for stress-induced cardiomyopathy.

DATA SOURCES

MEDLINE database search conducted from inception to August 2014, including the search terms "tako-tsubo," "stress-induced cardiomyopathy," "neurogenic cardiomyopathy," "neurogenic stress cardiomyopathy," and "transient left ventricular apical ballooning syndrome". In addition, references from pertinent articles were used for a secondary search.

STUDY SELECTION AND DATA EXTRACTION

After review of peer-reviewed original scientific articles, guidelines, and reviews resulting from the literature search described above, we made final selections for included references and data based on relevance and author consensus.

DATA SYNTHESIS

Stress-induced cardiomyopathy occurs most commonly in postmenopausal women. It can be precipitated by emotional stress, neurologic injury, and numerous other stress states. Patients may present with symptoms indistinguishable from acute coronary syndrome or with electrocardiogram changes and wall motion abnormalities on echocardiogram following neurologic injury. Nearly all patients will have an elevated cardiac troponin. The underlying etiology is likely related to release of catecholamines, both locally in the myocardium and in the circulation. Differential diagnosis includes myocardial infarction, myocarditis, neurogenic pulmonary edema, and nonischemic cardiomyopathy. Although the natural course of stress-induced cardiomyopathy is resolution, treatment strategies include sympathetic blockade and supportive care.

CONCLUSIONS

Stress-induced cardiomyopathy may mimic myocardial infarction and is an important condition to recognize in patients with underlying stress states, particularly neurologic injuries.

A case of "Tako-Tsubo syndrome" with postoperative shock

The “Tako-Tsubo syndrome” is a rare, transient, reversible hypokinesia of distal part of left ventricle, with normal coronary arteries. It was recently described and frequently associated with an extreme stressful event in postmenopausal women. We report a case of “Tako-Tsubo syndrome” following elective surgery for oesophageal malignancy with septic shock. Our report highlights the electrocardiographic changes with the progression of this syndrome and the challenges we faced in managing the case.

Epidemiology and pathophysiology of Takotsubo syndrome

Takotsubo syndrome is an acute cardiac syndrome first described in 1990 and characterized by transient left ventricular dysfunction affecting more than one coronary artery territory, often in a circumferential apical, mid-ventricular, or basal distribution. Several pathophysiological explanations have been proposed for this syndrome and its intriguing appearance, and awareness is growing that these explanations might not be mutually exclusive. The reversible apical myocardial dysfunction observed might result from more than one pathophysiological phenomenon. The pathophysiology of Takotsubo syndrome is complex and integrates neuroendocrine physiology, potentially involving the cognitive centres of the brain, and including the hypothalamic-pituitary-adrenal axis. Cardiovascular responses are caused by the sudden sympathetic activation and surge in concentrations of circulating catecholamines. The multiple morphological changes seen in the myocardium match those seen after catecholamine-induced cardiotoxicity. The acute prognosis and recurrence rate are now known to be worse than initially thought, and much still needs to be learned about the epidemiology and the underlying pathophysiology of this fascinating condition in order to improve diagnostic and treatment pathways.

Takotsubo syndrome (or apical ballooning syndrome) secondary to Zolmitriptan

Takotsubo syndrome (TS), also known as broken heart syndrome, is characterized by left ventricle apical ballooning with elevated cardiac biomarkers and electrocardiographic changes suggestive of an acute coronary syndrome (ie, ST-segment elevation, T wave inversions, and pathologic Q waves). We report a case of 54-year-old woman with medical history of mitral valve prolapse and migraines, who was admitted to the hospital for substernal chest pain and electrocardiogram demonstrated 1/2 mm ST-segment elevation in leads II, III, aVF, V5, and V6 and positive troponin I. Emergent coronary angiogram revealed normal coronary arteries with moderately reduced left ventricular ejection fraction with wall motion abnormalities consistent with TS. Detailed history obtained retrospectively revealed that the patient took zolmitriptan sparingly only when she had migraines. But before this event, she was taking zolmitriptan 2-3 times daily for several days because of a persistent migraine headache. She otherwise reported that she is quite active, rides horses, and does show jumping without any limitations in her physical activity. There was no evidence of any recent stress or status migrainosus. Extensive literature search revealed multiple cases of coronary artery vasospasm secondary to zolmitriptan, but none of the cases were associated with TS.

Evidence for an association between tako-tsubo cardiomyopathy and bronchial asthma: retrospective analysis in a primary care hospital

Objective:

We investigated the prevalence of bronchial asthma in patients with Tako-Tsubo Syndrome (TTS).

Design:

This retrospective case-series study was conducted in a primary care hospital in Zurich, Switzerland. Data of all patients with newly diagnosed TTS (2002 - 2012) were assessed electronically by the use of ICD-10. Asthma prevalence was compared to published epidemiologic data.

Setting:

Bronchial asthma is characterized by airway inflammation and, during attack, release of endogenous catecholamines. Sympathomimetic drugs are the mainstay of treatment for asthma patients. Likewise, catecholamine mediated diffuse microvascular myocardial dysfunction seems to be of critical importance for the development of TTS.

Results:

20 cases of TTS were identified. 90% were female, showed a median age of 70±13y [25y - 90y], an apical and/or midventricular ballooning pattern with preserved basal function and a median initial LVEF of 34±9% [25% - 55%]. 65% of patients underwent coronary angiography to rule out significant coronary artery disease. Hypertension was present in 45% of patients, 35% were smokers, none was suffering from diabetes. Prevalence of asthma in patients with TTS was significantly higher compared to the normal population (25% vs. 7%, p=0.012). In 30% of the TTS patients an iatrogenic cause for development of TTS was identified.

Conclusion:

Prevalence of asthma was significantly higher in patients with TTS compared to epidemiologic data from an age-matched population. Phenotypes of patients developing obstructive ventilatory disease and TTS might share common pathogenic mechanisms beyond the use of bronchodilatators. In addition, we identified other iatrogenic etiologies in patients with TTS.

Left ventricular strain modifications after maximal exercise in athletes: a speckle tracking study

PURPOSE

The increase in systolic indexes from rest (R) to exercise is achieved by combination of enhanced heart rate (HR) and stroke volume (SV). Aim of this study was to evaluate left ventricular (LV) longitudinal, circumferential, and torsional components immediately after a maximal intensity exercise (ME) by speckle tracking echocardiography (STE).

METHODS

Twenty-seven male water polo players performed an ME that consisted of 6 repeats of 100 m freestyle swim sets. An echocardiographic examination was performed before and after ME. STE was performed to obtain the analysis of LV myocardial deformation.

RESULTS

There were no differences between R and ME regarding LV longitudinal strains (PVLS). Apical circumferential LV strain (AVCS) and LV longitudinal strain rate (SR) increased at ME with respect to R (R: -23.1 ± 4.9%; ME: -28.4 ± 7.6%, P < 0.05; R: -1.1 ± 0.1/sec, ME: -1.5 ± 0.2/sec, P < 0.01). LV twisting (LVT) and untwisting (UTW) increased at ME (R: 7.9 ± 2.4°, ME: 14.2 ± 3.2°, P < 0.001; R: -107.2 ± 47.4; ME: -158.5 ± 61.5 °/sec; P < 0.01). At ME, apical rotation (Arot) had higher values than R values (5.4 ± 3.0°; 10.0 ± 6.0°; P < 0.01) and time-to-peak (TTP) of apical segments are earlier than all TTP. SV was related to LVT (r = 0.56, P = 0.01), AVCS (r = -0.59, P = 0.005) and Arot (r = 0.46, P = 0.04). At multivariate analysis, AVCS was the independent predictor of SV (β = -0.58; P < 0.05).

CONCLUSIONS

Apical fibers and LVT give the main contribution to systolic components at ME. The storage of energy during LVT, released during early diastole, seems to be a fundamental mechanism to support diastolic filling during maximal exercise.

Pheochromocytoma-Induced Inverted Takotsubo-Like Cardiomyopathy Leading to Cardiogenic Shock Successfully Treated With Extracorporeal Membrane Oxygenation

Pheochromocytoma classically displays a variety of rather benign symptoms, such as headache, palpitations, and sweating, although severe cardiac manifestations have been described. We report a case of pheochromocytoma-induced inverted takotsubo-like cardiomyopathy leading to shock and cardiac arrest successfully treated with extracorporeal membrane oxygenation (ECMO) as a bridge to pharmacological therapy and curative adrenalectomy. A previously healthy 46-year-old woman presented to the emergency department with abdominal pain, dyspnea, nausea, and vomiting. Clinical evaluation revealed cardiorespiratory failure with hypoxia and severe metabolic acidosis. Computed tomography (CT) scan showed pulmonary edema and a left adrenal mass. Transthoracic echocardiography (TTE) displayed severe left ventricular dysfunction with inverted takotsubo contractile pattern. Despite mechanical ventilation and inotropic and vasopressor support, asystolic cardiac arrest ensued. The patient was resuscitated using manual chest compressions followed by venoarterial ECMO. Repeated TTEs demonstrated resolution of the cardiomyopathy within a few days. Laboratory results indicated transient renal and hepatic dysfunction, and CT scan of the brain displayed occipital infarctions. Biochemical testing and radionuclide scintigraphy confirmed a pheochromocytoma. Pharmacological adrenergic blockade was instituted prior to delayed adrenalectomy after which the diagnosis was histopathologically verified. The patient recovered after rehabilitation. We conclude that pheochromocytoma should be considered in patients presenting with unexplained cardiovascular compromise, especially if they display (inverted) takotsubo contractile pattern. Timely, adequate management might involve ECMO as a bridge to pharmacological therapy and curative surgery.

Characterizing genetic variation of adrenergic signalling pathways in Takotsubo (stress) cardiomyopathy exomes

AIMS

Exome sequencing was used to genotype comprehensively a Takotsubo (stress) cardiomyopathy (TC) cohort, enabling investigation of a vast 486 gene network for adrenergic signalling.

METHODS AND RESULTS

Twenty-eight TC subjects, including a mother-daughter pair and five recurrent cases, underwent whole-exome sequencing. Frequencies of 17 common, functional adrenergic polymorphisms were statistically similar to those of population controls. Filtering for rare, predicted-deleterious, catecholamine/adrenergic signalling variants revealed heterozygosity in 55 genes in TC cases and 59 genes in healthy controls. Overall allele burden was similar and did not discriminate clinical variables among TC subjects, but gene identities were largely cohort specific, and TC cases were enriched for variants within functional domains (68% vs. 48%, P = 0.031). Two-thirds of TC cases carried more than one filtered adrenergic pathway variant, and 11 genes harboured a variant in ≥ 2 cases. The mother-daughter pair shared missense variants in highly conserved functional domains of ADH5, CACNG1, EPHA4, and PRKCA. An adrenergic pathway-independent analysis of the cohort exposed no common gene for TC.

CONCLUSIONS

Overall, these data support genetic heterogeneity in TC susceptibility and a likely polygenic basis, conferring a cumulative effect on adrenergic pathway dysregulation in a subset of individual subjects. Study of larger cohorts and non-coding regulatory regions is warranted to define genetic risk factors for TC further.

Takotsubo syndrome (stress cardiomyopathy): an intriguing clinical condition in search of its identity

Takotsubo syndrome is a relatively frequent clinical entity presenting typically as an acute coronary syndrome in the absence of obstructive coronary artery disease and characterized angiographically by transient left ventricular systolic dysfunction, sparing the basal segments of the left ventricle ("apical ballooning"). Takotsubo syndrome characteristically affects peri- or postmenopausal women, albeit recent series show that men also are at risk. Takotsubo syndrome is characteristically triggered by severe emotional or physical stress, which suggests a pathogenic role for increased sympathetic activity leading to myocardial perfusion abnormalities and ventricular dysfunction. The reasons why severe emotional and physical stress result in the development of takotsubo syndrome in certain individuals but not others is still a matter of speculation, but strongly suggests the existence of predisposing factors/mechanisms in certain subjects. The present article reviews the different factors that can play a role in the development of takotsubo syndrome in different patients. We propose that triggers (ie, emotional stressors, physical stressors, iatrogenic stressors, and neurologic triggers), pathogenic mechanisms (ie, increased catecholamine levels, coronary vasomotor abnormalities leading to myocardial ischemia), and predisposing factors (ie, cardiovascular risk factors, endothelial dysfunction, comorbidities) all interact in a complex fashion and possibly differently in different patients to cause takotsubo syndrome. Identifying these factors may help in preventing and managing the condition more effectively.

Tako-tsubo cardiomyopathy: how to understand possible pathophysiological mechanism and the role of (123)I-MIBG imaging

Tako-tsubo cardiomyopathy (TCM) is an increasingly recognized clinical syndrome characterized by acute reversible apical ventricular dysfunction, commonly preceded by exposure to severe physical or emotional stress. In this review, we give a short overview on clinical presentation and treatment of TCM and discuss the possible pathophysiological mechanisms of TCM and the role of various non-invasive imaging modalities in TCM with a focus on the potential role of (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy. Currently, the dominating hypothesis on the pathophysiology of TCM postulates that high levels of the neurotransmitter epinephrine may trigger a change in intracellular signaling in ventricular myocytes. More specific, epinephrine stimulates G-protein coupled β2 adenoreceptors (β2AR) which are located on ventricular myocytes. Normal levels of this neurotransmitter predominantly stimulate the intracellular G-protein, and induce a positive inotropic effect. However, with significant increasing levels of epinephrine, the predominance of stimulation is shifted from G-stimulating to the G-inhibitor protein coupling, which leads to a negative inotropic effect. Interestingly, this negative inotropic effect is the largest in the apical myocardium where the β2AR:β1AR ratio is the highest within the heart. Echocardiography and ventriculography are essential to diagnose TCM, but new imaging tools are promising to diagnose TCM and to evaluate therapeutic efficacy. Cardiovascular magnetic resonance can be used to differentiate TCM from other myocardial diseases, such as myocarditis. (123)I-meta-iodobenzylguanidine ((123)I-MIBG) scintigraphy can be used to assess ventricular adrenergic activity and may guide optimization of individual (pharmacological) therapy. These new insights into the possible pathophysiological mechanisms and novel diagnostic imaging modalities can be used as starting point for the development of international guidelines of TCM which may increase the awareness, and optimize the treatment of TCM.

Takotsubo cardiomyopathy: Pathophysiology, diagnosis and treatment

In 1990, takotsubo cardiomyopathy (TCM) was first discovered and reported by a Japanese cardiovascular specialist. Since then, this heart disease has gained worldwide acceptance as an independent disease entity. TCM is an important entity that differs from acute myocardial infarction. It occurs more often in postmenopausal elderly women, is characterized by a transient hypokinesis of the left ventricular (LV) apex, and is associated with emotional or physical stress. Wall motion abnormality of the LV apex is generally transient and resolves within a few days to several weeks. Its prognosis is generally good. However, there are some reports of serious TCM complications, including hypotension, heart failure, ventricular rupture, thrombosis involving the LV apex, and torsade de pointes. It has been suggested that coronary spasm, coronary microvascular dysfunction, catecholamine toxicity and myocarditis might contribute to the pathogenesis of TCM. However, its pathophysiology is not clearly understood.

Functional and histological assessment of an experimental model of Takotsubo's cardiomyopathy

BACKGROUND

Our objectives were to characterize functional and structural features of an experimental model of Takotsubo cardiomyopathy, and its response to beta-blockers.

METHODS AND RESULTS

In protocol 1, a dose-finding study: 69 rats received various doses of isoproterenol (ISO) and echocardiographic and histologic parameters were measured on days 2 to 3 or day 8. There were no dose-dependent effects and, out of 69 ISO-treated rats, 40 (58.0%) survived and 29 (42.0%) died within 24 hours. Of survivors, 30 had apical akinesis averaging 12.1 ± 1.6% of the long axis LV circumference. Out of the 40 survivors, 32.5% showed apical akinesis ≥ 10%, 42.5% showed akinesis<10% and 25% showed no apical akinesis. The basal portion of the LV was always preserved. At 24 hours, histology and ultrastructure showed necrosis, vacuolization, lipid droplets, mononuclear cell infiltration, damaged mitochondria, and edema. On day 8, apical akinesis fully resolved but histologic abnormalities were still present. In protocol 2, rats were randomized to Control; ISO100 mg/kg; propranolol+ISO; and metoprolol+ISO groups. Pretreatment with propranolol and metoprolol improved survival to 90% and 100% respectively, compared with 60% in the ISO group, but did not reduce the incidence and extent of akinesis or the structural damage.

CONCLUSION

TC can be mimicked in a rat model of ISO exposure that demonstrates apical akinesis on days 2 to 3 with full recovery of systolic regional wall motion abnormality despite the presence of persistent foci of necrosis and fibrosis on day 8. Pretreatment with beta-blockers improved survival but did not affect structural and functional alterations.

Pathophysiology of takotsubo syndrome: temporal phases of cardiovascular responses to extreme stress

Takotsubo syndrome (TTS), also known as takotsubo cardiomyopathy, is an acute heart failure syndrome that typically occurs after a period of great emotional stress. The archetypal patient is a postmenopausal woman who presents with chest pain, ST-segment elevation and acute hypokinesia of the apical and middle segment of the left ventricle that extends beyond the territory of a single coronary artery, coupled with hyperkinesia of the basal myocardium. Recent preclinical and clinical studies have shown the importance of high catecholamine levels in precipitating TTS. We propose that this is caused by activation of β-adrenoceptors and the subsequent activation of a negatively-inotropic pathway, perhaps to protect the heart from catecholamine overload. We explore the pathophysiology of TTS according to its "phases", both preclinically and clinically. This will show that the condition is not one of static apical hypokinesia that simply improves, but rather a dynamic condition that changes as the disease progresses. We hope that further exploration of TTS using its "phases" will aid in its characterization, diagnosis and treatment.

Takotsubo cardiomyopathy and anaesthesia: case report and review of the literature

Takotsubo cardiomyopathy is an acute syndrome characterized by cardiac failure from disturbances in the contractility of the left ventricle. It is presumably caused by sympathetic over stimulation. We describe a case of postoperatively developed Takotsubo cardiomyopathy in a 69-year-old female. The syndrome developed in connection with awareness during complete residual paralysis. The literature on this syndrome is reviewed and implications for anaesthesia described.

Takotsubo cardiomyopathy a short review

Takotsubo cardiomyopathy (TCM), otherwise cardiomyopathy,apical ballooning syndrome or broken heart syndrome is a reversible cardiomyopathy, predominantly occurs in post-menopausal women and commonly due to emotional or physical stress. Typically, patients present with chest pain and ST elevation or T wave inversion on their electrocardiogram mimicking acute coronary syndrome, but with normal or non-flow limiting coronary artery disease. Acute dyspnoea, hypotension and even cardiogenic shock may be the presenting feature of this condition. The wall motion abnormalities typically involve akinesia of the apex of the left ventricle with hyperkinesia of the base of the heart. Atypical forms of TCM have also recently been described. An urgent left ventriculogram or echocardiogram is the key investigation to identify this syndrome. Characteristically, there is only a limited release of cardiac enzymes disproportionate to the extent of regional wall motion abnormality. Transient right ventricular dysfunction may occur and is associated with more complications, longer hospitalisation and worse left ventricular systolic dysfunction. Recently, cardiac MRI has been increasingly used to diagnose this condition and to differentiate from acute coronary syndrome in those who have abnormal coronary arteries. Treatment is often supportive, however beta-blocker and angiotensin-converting enzyme inhibitor or angiotensin II receptor blocking agent are being used in routine clinical practice. The syndrome is usually spontaneously reversible and cardiovascular function returns to normal after a few weeks. This review article will elaborate on the pathophysiology, clinical features including the variant forms, latest diagnostic tools, management and prognosis of this condition.

Takotsubo cardiomyopathy, a two-stage recovery of left ventricular systolic and diastolic function as determined by cardiac magnetic resonance imaging

AIMS

Takotsubo cardiomyopathy (TTC) is an entity mimicking acute myocardial infarction, characterized by transient severe systolic heart failure. Echocardiographic studies suggest that diastolic dysfunction is present in TTC at presentation; however, no reports exist regarding the time course of left ventricular (LV) recovery. This study describes the recovery of LV systolic and diastolic function in TTC. We hypothesized that, in TTC, there is diastolic dysfunction at admission, and that recovery is delayed compared with systolic function.

METHODS AND RESULTS

We enrolled (consecutively 2010-12) 16 patients (mean age 66, range 39-84 years) diagnosed with TTC and 20 healthy matched controls. We performed cardiac magnetic resonance imaging (CMR) at admission, pre-discharge, and 3-month follow-up. Diastolic function was assessed by LV peak filling rate (LVPFR) and left atrial (LA) emptying volumes. At admission, LV ejection fraction was low, increased at pre-discharge (37 ± 6 vs. 58 ± 6%, P < 0.001), and normalized at follow-up (to 65 ± 5%, P = 0.01). LVPFR did not increase during hospitalization (80 ± 3 vs. 89 ± 4 mL/s/m(2), P = 0.21), but was normalized at follow-up (to 206 ± 19, P < 0.001; controls, 214 ± 13, P = 0.23). During hospitalization, LA passive emptying volume remained low (6 ± 2 vs. 8 ± 3 mL/m(2), P = 0.05) and LA active emptying volume remained high (17 ± 3 vs. 16 ± 3 mL/m(2), P = 0.71), whereas LA conduit volume increased (7 ± 3 vs. 23 ± 4 mL/m(2), P < 0.001). T2-weighted imaging demonstrated non-coronary distributed apical oedema without contrast enhancement.

CONCLUSION

Patients with TTC undergo fast systolic recovery. However, at discharge, profound diastolic dysfunction is demonstrated by CMR. At follow-up, both LV systolic and diastolic function is normalized in patients with recovered TTC.

Takotsubo cardiomyopathy associated with thyrotoxicosis: a case report and review of the literature

BACKGROUND

Takotsubo or stress-induced cardiomyopathy is a form of reversible cardiomyopathy commonly associated with emotional or physical stress. Thyrotoxicosis has been identified as a rare cause of Takotsubo cardiomyopathy, with only 12 cases reported in the literature. Here, we report a case of thyroid storm presenting with Takotsubo cardiomyopathy in the setting of Graves' disease.

PATIENT FINDINGS

A 71-year-old woman presented with abdominal pain, vomiting, confusion, and history of weight loss. She was initially diagnosed and treated for diabetic ketoacidosis at another hospital and was transferred to our hospital one day after initial presentation because of concern for acute coronary syndrome. A diagnosis of Takotsubo cardiomyopathy was made on the basis of cardiac catheterization. At that time, she was diagnosed and treated for thyroid storm. Follow-up 7 weeks later revealed improvement of her cardiac function and near-normalization of thyroid hormone levels.

SUMMARY

In this patient, who presented with symptoms of heart failure, acute coronary syndrome was initially considered, but the diagnosis of Takotsubo cardiomyopathy associated with thyroid storm was ultimately made based on cardiac catheterization and laboratory investigation.

CONCLUSIONS

Thyrotoxicosis is associated with adverse disturbances in the cardiovascular system. Takotsubo cardiomyopathy could be a presenting manifestation of thyroid storm, perhaps related to excess catecholamine levels or sensitivity.

Mechanisms of stress (takotsubo) cardiomyopathy

Stress cardiomyopathy is a form of reversible systolic dysfunction of the mid and apical left ventricle with pathologic changes of the electrocardiogram in the absence of an obstructive coronary artery disease. The prevalence of stress cardiomyopathy among patients with symptoms suggestive of myocardial infarction is 0.7% to 2.5%, and it is found predominantly in postmenopausal women (90%). No large studies have confirmed the cause of stress cardiomyopathy. Published data suggest that substantially elevated plasma catecholamine levels, due to emotional or physical stress, may be relevant.

Clinical management of takotsubo cardiomyopathy

The clinical management of takotsubo cardiomyopathy is challenging. Its diagnosis must be made on clinical grounds and differentiated from alternative diagnoses with echocardiography, serum biomarkers, cardiac catheterization, and cardiac magnetic resonance imaging. Acute therapy includes supportive care, targeting the precipitating trigger if known, b-blockade, inhibitors of the renin-angiotensin system, and consideration of systemic anticoagulation in all patients. Recovery of left ventricular function to normal is expected regardless of early therapy. Although the prognosis is generally favorable, monitoring for early dangerous complications is essential. There is no evidence to support use of long-term medical therapy to reduce the risk of recurrence.

Acute cardiac sympathetic disruption in the pathogenesis of the takotsubo syndrome: a systematic review of the literature to date

Takotsubo syndrome (TS), also known as broken heart syndrome and neurogenic stunned myocardium, is an acute cardiac disease entity characterized by a clinical picture mimicking that of an acute coronary syndrome. The pathogenesis of TS has not been established yet. Among the most often debated pathologic mechanisms of TS are as follows: first, multi-vessel coronary spasm; second, myocardial microvascular dysfunction; third, aborted myocardial infarction caused by transient thrombotic occlusion of a long wrap-around left anterior descending artery; fourth, left ventricular outflow tract obstruction; fifth, blood-borne catecholamine cardiac toxicity; and sixth, cardiac sympathetic disruption and norepinephrine seethe and spillover. The aim of this review is to provide a thorough analysis of the literature data coming mainly from the neurological literature and dealing with the pathogenesis of TS. Substantial evidence challenging the first five hypotheses and arguing in favor of the hypothesis that acute cardiac sympathetic eruption and norepinephrine seethe and spillover is causing TS in predisposed patients is presented.

Adrenergic nervous system in heart failure: pathophysiology and therapy

Heart failure (HF), the leading cause of death in the western world, develops when a cardiac injury or insult impairs the ability of the heart to pump blood and maintain tissue perfusion. It is characterized by a complex interplay of several neurohormonal mechanisms that become activated in the syndrome to try and sustain cardiac output in the face of decompensating function. Perhaps the most prominent among these neurohormonal mechanisms is the adrenergic (or sympathetic) nervous system (ANS), whose activity and outflow are enormously elevated in HF. Acutely, and if the heart works properly, this activation of the ANS will promptly restore cardiac function. However, if the cardiac insult persists over time, chances are the ANS will not be able to maintain cardiac function, the heart will progress into a state of chronic decompensated HF, and the hyperactive ANS will continue to push the heart to work at a level much higher than the cardiac muscle can handle. From that point on, ANS hyperactivity becomes a major problem in HF, conferring significant toxicity to the failing heart and markedly increasing its morbidity and mortality. The present review discusses the role of the ANS in cardiac physiology and in HF pathophysiology, the mechanisms of regulation of ANS activity and how they go awry in chronic HF, methods of measuring ANS activity in HF, the molecular alterations in heart physiology that occur in HF, along with their pharmacological and therapeutic implications, and, finally, drugs and other therapeutic modalities used in HF treatment that target or affect the ANS and its effects on the failing heart.

Left ventricular apical ballooning syndrome in men: a case series

OBJECTIVES

Apical ballooning syndrome usually involves elderly women. We reported the profile of this syndrome in men.

METHODS

We identified 54 consecutive patients with the syndrome: among them, seven were men (13%, group M) and 47 were women (87%, group F).

RESULTS

Men were younger than women (group M 61.7 years vs. group F 72.8 years, median age, P < 0.01) and emotional triggers predominated in women ( group M 14.3% vs. group F 44.7%, P = 0.01) compared with physiological ones which were more frequent in men (group M 42.9% vs. group F 19.1%, P = 0.02). At onset, men were more compromised than women (group M 42.9% vs. group F 6.4%, P = 0.004). At the median follow-up of 18.5 months, more men died than women (group M 28.6% vs. group F 8.5%, P = NS), but only women had cardiac-related deaths (group M 0% vs. group F 6.4%, P = NS). Cardiac outcome was similar in both groups (group M 14.3% vs. group F 23.4%, P = NS). Left ventricular ejection fraction increased in both sexes from 41% to more than 56% (P < 0.01).

CONCLUSION

In this small case series, left ventricular apical ballooning syndrome showed similar features in both sexes. However, men seemed to be more affected at younger age, presented more physiological triggers and more compromised clinical status at admission. Despite this, cardiac outcome was good in both sexes.

Recurrent left ventricular apical ballooning syndrome in a patient with pheochromocytoma

Transient left ventricular apical ballooning syndrome is characterized by reversible left ventricular wall motion abnormalities, chest pain or dyspnea, ST-segment elevation, and mild elevation of cardiac enzyme levels in the absence of obstructive coronary artery disease. The pathophysiology of the syndrome is still unknown. The probable mechanism is supposed to be a catecholamine discharge. We report the case of a 66-year-old woman with recently diagnosed pheochromocytoma who presented with chest pain and ST-segment elevation. Coronary angiography revealed normal coronaries and apical dyskinesia at ventriculography. A similar episode of chest pain occurred 4 years ago with same angiographic findings and reversible inferobasal akinesia. In-hospital course was uneventful and the patient was discharged from the hospital 4 days later with treatment of aspirin 1 × 100 mg, metoprolol 1 × 50 mg, lisinopril 1 × 10 mg, and atorvastatin 1 × 20 mg. At 2 years follow-up after the event, the patient remained asymptomatic.

Novel rat model reveals important roles of β-adrenoreceptors in stress-induced cardiomyopathy

BACKGROUND

Stress-induced cardiomyopathy (SIC), also known as Takotsubo cardiomyopathy, is an acute cardiac syndrome with substantial morbidity and mortality. The unique hallmark of SIC is extensive ventricular akinesia involving apical segments with preserved function in basal segments. Adrenergic overstimulation plays an important role in initiating SIC but the pathophysiological pathways and receptors involved are unknown.

METHODS

Sprague Dawley rats (~300 g) were injected with a single dose of the β-adrenergic agonist isoprenaline (ISO, i.p.) and echocardiography was used to study cardiac function. The akinetic part of the left ventricle was biopsied in six SIC patients. Amount of intracellular lipid and glycogen as well as degree of permanent cardiac damage were assessed by histology.

RESULTS

In rats, ISO at doses ≥ 50 mg/kg induced severe SIC-like regional akinesia that completely resolved within seven days. Intracellular lipid content was higher in akinetic, but not in normokinetic myocardium in both SIC patients and rats. β2-receptor blockade or Gi-pathway inhibition was associated with less widespread akinesia and low lipid accumulation but significantly increased acute mortality.

CONCLUSIONS

We provide a novel rat model of SIC that supports the hypothesis of circulating catecholamines as initiators of SIC. We propose that the β-adrenoreceptor pathway is important in the setting of severe catecholamine overstimulation and that perturbations of cardiac metabolism occur in SIC.

Cardiac complications as initial manifestation of pheochromocytoma: frequency, outcome, and predictors

OBJECTIVE

To examine the frequency, outcome, and clinical predictors of cardiac complications as the initial manifestation of pheochromocytoma.

METHODS

The medical records of all 76 patients with pheochromocytoma or functional paraganglioma treated at Cedars-Sinai Medical Center, Los Angeles, California, from 1995 to 2011 were reviewed. The patients initially presenting with cardiac complications were identified, and their clinical, laboratory, and imaging characteristics were compared with those of the patients presenting with other complaints, especially hypertension and adrenal mass.

RESULTS

Of the 76 patients, 9 (12%) presented with the following: 2 with acute heart failure, 1 with left ventricular thrombus, 3 with myocardial infarction, and 3 with severe arrhythmia. Failure to diagnose pheochromocytoma resulted in unnecessary invasive interventions in 2 patients. Recovery of cardiac function was excellent after resection of the tumor in all patients. In comparison with the 67 patients presenting with other complaints, the 9 with cardiac complications had similar demographics and cardiac risk factors but harbored larger tumors (6.7 ± 0.8 cm versus 4.4 ± 0.3 cm; P = .015) and exhibited higher biochemical marker levels (23.9 ± 9.0-fold versus 11.3 ± 2.4-fold; P = .082), longer corrected QT interval (473 ± 8 ms versus 443 ± 6 ms; P = .015), and lower ejection fraction (43% ± 8% versus 66% ± 2%; P = .002).

CONCLUSION

In this study, 12% of patients with pheochromocytoma initially presented with cardiac complications. Patients with large tumors and high levels of biochemical markers were more likely to develop cardiac injury. Our results confirm that the presence of pheochromocytoma should be ruled out in patients with cardiac diseases and features suggesting pheochromocytoma so that unnecessary interventions can be avoided and cardiac recovery can be achieved.

Takotsubo-like myocardial dysfunction accompanied with cerebellar hemorrhage

We report a 71-year-old woman with takotsubo-like myocardial dysfunction accompanied with cerebellar hemorrhage. On admission time, although she was unconscious by cerebellar hemorrhage, no obvious heart failure and serological disorder were observed. Three days later, operation for extraventricular drainage was performed. However, conscious level did not change. Four days after admission, the change of electrocardiogram wave pattern and the decrement of heart wall motion were detected. These findings revealed takotsubo-like myocardial dysfunction had occurred. Physical stresses by cerebellar hemorrhage and cranial operation might cause cardiac disorder. This is a remarkable case of takotsubo-like myocardial dysfunction, which is brought about cerebellar hemorrhage against subarachnoid hemorrhage.

Repeat recurrence of takotsubo cardiomyopathy related to inhaled beta-2-adrenoceptor agonists

Takotsubo cardiomyopathy (also referred to as transient apical ballooning syndrome, broken heart syndrome or stress cardiomyopathy) is an increasingly recognized entity in the western world typically characterized by reversible left ventricular dysfunction that develops in the setting of acute severe emotional or physical stress. Increased catecholamine levels have been proposed to play a central role in the pathogenesis of the disease, although the specific pathophysiology of this condition remains elusive at the present moment. In recent times, there have been reports of takotsubo cardiomyopathy (TC) following medical interventions such as invasive or surgical procedures or specific medical regimens. In the current report, we present a patient with multiple recurrences of TC triggered by the same medical therapeutic intervention; in our particular case, repetitive exposure to inhaled beta-2-adrenoceptor agonist.