Increased responsiveness of left ventricular apical myocardium to adrenergic stimuli

Transient left ventricular dysfunction (tako-tsubo phenomenon): Findings and potential pathophysiological mechanisms

Tako-tsubo-like left ventricular dysfunction phenomenon (TTP) is characterized by transient left ventricular apical ballooning associated with symptoms, electrocardiographic changes and minimal cardiac enzyme release in the absence of coronary artery disease. Initially described in Japan, TTP occurs worldwide, predominantly in women and frequently after emotional or physical stress. Symptoms include anginal chest pain, dyspnea and syncope. Electrocardiographic ST elevations may be present only for several hours, and are followed by negative T waves that persist for months. Arterial hypertension is found in up to 76% of TTP patients, hyperlipidemia in up to 57% and diabetes mellitus in up to 12%. Potential pathophysiological mechanisms for TTP include catecholamine-induced myocardial stunning or hyperkinesis of the basal left ventricular segments, coronary vasospasm, plaque rupture, myocarditis and genetic factors. TTP patients should be monitored similarly to myocardial infarction patients because organ failure, cardiogenic shock, ventricular fibrillation or rupture may occur. Beta-blockers are indicated, whereas catecholamines and nitrates should be avoided. The long-term prognosis is unknown.

Takotsubo cardiomyopathy--transient left ventricular apical ballooning mimicking acute myocardial infarction

Takotsubo cardiomyopathy is characterized by transient left ventricular dysfunction with clinical symptoms of chest pain, electrocardiographic changes of ST-segment elevation or T wave inversion, which mimics acute myocardial infarction in patients without angiographically significant coronary artery stenosis. We report a 75-year-old woman with a history of chest tightness who presented with typical pictures of takotsubo cardiomyopathy. Acute myocardial infarction was initially diagnosed based on the electrocardiographic changes and elevated troponin. Apical akinesis and ballooning with basal hyperkinesis were noted during left ventriculography. Coronary angiography, however, did not show significant coronary artery stenosis. Electrocardiography was normal 3 months later. Follow-up echocardiography did not show any wall motion abnormality. This patient remained well without chest pain or dyspnea over 24 months of follow-up. Optimal medical management of takotsubo cardiomyopathy remains unclear. This patient received diltiazem to prevent possible coronary artery spasm. The prognosis of this syndrome seems to be favorable except for occasional mortality due to left ventricular rupture or ventricular arrhythmia. Recurrence of this syndrome is rare.

Clinical features of transient left ventricular apical ballooning

This report describes the clinical characteristics of 8 consecutive patients with transient left ventricular apical ballooning identified among 389 patients (2%) admitted to a tertiary referral hospital with suspected acute coronary syndromes over a 1-year period. Among these patients, 2 cases appeared to be caused by acute myocarditis and 1 case by head trauma with intracranial bleeding. In the remaining 5 cases, no apparent cause was found. All patients but 1 were postmenopausal women (mean age 60 +/- 13.5 years). Preceding strong emotional or physical stress was present in 6 patients. The presenting symptom in 7 patients was chest pain. Four patients had significant ST-segment elevation, and the remaining 4 had T-wave inversions on their admission electrocardiograms. Mean peak troponin I was moderately elevated (3.7 +/- 4.5 ng/dl). The mean echocardiographic left ventricular ejection fraction was 40 +/- 10% on admission and increased significantly to 63 +/- 4% at 1-month follow-up (p <0.0001). All patients but 1 had abnormal corrected Thrombolysis In Myocardial Infarction frame counts (>27 frames) in >or=1 major epicardial coronary artery. All patients were alive and without major adverse cardiac events at 6-month follow-up. In conclusion, transient left ventricular apical ballooning should be considered in the differential diagnosis of patients presenting with suspected acute coronary syndromes, because it may account for approximately 2% of hospital admissions.

Acute impairment of regional myocardial glucose uptake in the apical ballooning (takotsubo) syndrome

BACKGROUND

Apical ballooning syndrome (ABS) is a poorly understood clinical entity characterized by acute, transient systolic dysfunction of the left ventricular (LV) apex in the absence of epicardial coronary artery disease and commonly associated with acute emotional stress. We report abnormal regional myocardial perfusion and glucose uptake in 4 consecutive ABS patients studied using positron emission tomography with 13N-ammonia and 18F-fluorodeoxyglucose within 72 hours of presentation with ABS.

METHODS

All patients were postmenopausal females, 3 of whom had a major recent life stress event. Coronary angiography revealed no or minimal obstructive epicardial coronary artery disease. All patients exhibited reduced glucose uptake in the mid-LV and apical myocardial segments, which was out of proportion to perfusion abnormalities in half of the cases.

CONCLUSION

In all 4 patients, affected regions subsequently recovered regional LV systolic function within 6 weeks.

Acute impairment of regional myocardial glucose uptake in the apical ballooning (takotsubo) syndrome

BACKGROUND

Apical ballooning syndrome (ABS) is a poorly understood clinical entity characterized by acute, transient systolic dysfunction of the left ventricular (LV) apex in the absence of epicardial coronary artery disease and commonly associated with acute emotional stress. We report abnormal regional myocardial perfusion and glucose uptake in 4 consecutive ABS patients studied using positron emission tomography with 13N-ammonia and 18F-fluorodeoxyglucose within 72 hours of presentation with ABS.

METHODS

All patients were postmenopausal females, 3 of whom had a major recent life stress event. Coronary angiography revealed no or minimal obstructive epicardial coronary artery disease. All patients exhibited reduced glucose uptake in the mid-LV and apical myocardial segments, which was out of proportion to perfusion abnormalities in half of the cases.

CONCLUSION

In all 4 patients, affected regions subsequently recovered regional LV systolic function within 6 weeks.

Tako-tsubo syndrome: a potential role for cytomegalovirus infection

The tako-tsubo syndrome is a transient cardiomyopathy of unknown origin, which mimics acute ST-elevation myocardial infarction in the absence of obstructive epicardial coronary artery disease. This novel syndrome is characterized by chest pain, ST-segment changes, minimal enzymatic release, and balloon-like asynergy of the apical region. We report a case of tako-tsubo syndrome associated with acute cytomegalovirus infection and discuss the possible role of a viral aetiology in the onset of this syndrome.

Transient left ventricular apical ballooning after cocaine use: is catecholamine cardiotoxicity the pathologic link?

We describe a patient who developed acute chest pain after using cocaine and had ST-segment elevation in the anterior leads on electrocardiography with mild elevation of cardiac enzymes. Cardiac catheterization showed normal coronary arteries with no coronary vasospasm. Left ventricular angiography revealed typical ballooning of the left ventricular apex during systole with an estimated left ventricular ejection fraction of 25%. The symptoms improved during the next few hours, and follow-up echocardiography 4 days later showed complete resolution of the left ventricular dysfunction. Transient left ventricular apical ballooning (LVAB) was diagnosed. To our knowledge, LVAB (also known as Takotsubo cardiomyopathy or "broken heart syndrome") has not been reported previously in association with cocaine use. We discuss the possible pathophysiologic link between LVAB and cocaine-induced cardiotoxicity.

Apical ballooning syndrome or takotsubo cardiomyopathy: a systematic review

AIMS

To clarify the major features of the apical ballooning syndrome, we performed a systematic review of the existing literature.

METHODS AND RESULTS

Review of all relevant case series using the MEDLINE and EMBASE databases resulted in the identification of 14 studies. These studies suggest that the apical ballooning syndrome accounts for approximately 2.0% of ST-segment elevation infarcts, with most cases described in post-menopausal women. The most common clinical presentations are chest pain and dyspnoea, reported in 67.8 and 17.8% of the patients, respectively. Cardiogenic shock (4.2% of the patients) and ventricular fibrillation (1.5%) were not infrequent. ST-segment elevation was reported in 81.6% of the patients, T wave abnormalities in 64.3%, and Q waves in 31.8%. Cardiac biomarkers were usually mildly elevated, as reported in 86.2% of the patients. Typically, patients had left ventricular (LV) dysfunction on admission, with mean ejection fraction ranging from 20 to 49%. However, over a period of days to weeks, all patients experienced dramatic improvement in LV function. The onset of symptoms was often preceded by emotional (26.8%) or physical stress (37.8%). Norepinephrine concentration was elevated in 74.3% of the patients. Prognosis was generally excellent, with full recovery in most patients. In-hospital mortality was 1.1%. Only 3.5% of the patients experienced a recurrence.

CONCLUSION

Clinicians should consider this syndrome in the differential diagnosis of patients presenting with chest pain, especially in post-menopausal women with a recent history of emotional or physical stress.

Echocardiography and reversible left ventricular dysfunction

PURPOSE

Transient apical ballooning is increasingly recognized in acutely ill, hospitalized patients. This article reviews clinical aspects of the syndrome, its recognition by echocardiography, and will review other disorders whose recognition is due primarily to the availability of echocardiography.

METHODS

Systematic review of the medical literature concerning the syndrome of transient apical ballooning.

RESULTS

Seven recent studies of transient apical ballooning are reviewed; the clinical characteristics, biomarker data, echocardiographic findings, and angiographic data are remarkably similar. Most afflicted individuals are women in their seventh decade who develop chest symptoms in close relationship to a "trigger" event--this is usually either severe emotional distress, a medical illness, or a procedure.

CONCLUSIONS

Transient apical ballooning is not uncommonly encountered among acutely ill, hospitalized patients with chest symptoms. As yet there is no consensus of the underlying mechanism, although there is reason to believe that catecholamine injury to the myocardium is partially, if not wholly responsible. The widespread use of echocardiography appears to be responsible for the increasing recognition of this (and other) syndromes.

Apical ballooning syndrome in a postoperative patient with normal microvascular perfusion by myocardial contrast echocardiography

Apical ballooning syndrome is classically described as transient left ventricular (LV) dysfunction, marked LV akinesia, and normal or near-normal coronary arteries. The etiology is unclear and there is limited information based on case reports and small case series. We describe a 35-year-old woman who underwent surgical hepatectomy and developed apical ballooning syndrome in the postoperative period. The novel use of myocardial contrast echocardiography (MCE) in this setting demonstrated intact microvascular perfusion and lack of coronary flow-limiting abnormalities despite apical akinesis. In select patients with similar clinical presentations, performing MCE is safe and may be pursued as an alternative to invasive coronary angiography.

Transient left ventricular apical ballooning in a community hospital in Germany

INTRODUCTION

Tako-tsubo cardiomyopathy represents an intermittent left ventricular dysfunction with a ballooning of the left ventricular apical myocardium without significant coronary artery disease. Precise epidemiological data are not yet available.

METHODS AND RESULTS

We retrospectively reviewed 16,989 cases with diagnostic angiographies in our catheter laboratory from January 2001 until December 2004 for intermittent left ventricular apical ballooning. Thirty-two (0.2%) patients were included (50% of all cases presented in 2004, 50% of all cases during the summer months). Twenty-nine (91%) were female, median age was 67.5 years. Fourteen patients (44%) were known to have chronic obstructive pulmonary disease or asthma. Thirteen patients (41%) reported an acute stressful event prior to onset of symptoms. Twenty-five (78%) of the patients presented with clinical signs of an acute coronary syndrome with positive troponin T in 20 (63%) patients. Median left ventricular ejection fraction was 42.5%. Follow-up data of 30 patients (94%) could be obtained; median follow-up time is 6 months. Two patients died during follow-up (malignancy; unknown cause). Echocardiography was performed in 26 (81%) patients; median ejection fraction was 70%.

CONCLUSION

Tako-tsubo-like cardiomyopathy might be considered a differential diagnosis for acute coronary syndrome especially in elderly women. Chronic pulmonary diseases may be associated with a higher risk. The reason for the increasing number of cases during the last year is not clear; however, the tendency for early angiography in acute coronary syndrome may have contributed. The reason for the accumulation of cases during the summer months is also not yet understood.

Acute and reversible cardiomyopathy provoked by stress in women from the United States

BACKGROUND

A clinical entity characterized by acute but rapidly reversible left ventricular (LV) systolic dysfunction and triggered by psychological stress is emerging, with reports largely confined to Japan.

METHODS AND RESULTS

Over a 32-month period, 22 consecutive patients with this novel cardiomyopathy were prospectively identified within a community-based practice in the Minneapolis-St. Paul, Minn, area. All patients were women aged 32 to 89 years old (mean 65+/-13 years); 21 (96%) were > or =50 years of age. The syndrome is characterized by (1) acute substernal chest pain with ST-segment elevation and/or T-wave inversion; (2) absence of significant coronary arterial narrowing by angiography; (3) systolic dysfunction (ejection fraction 29+/-9%), with abnormal wall motion of the mid and distal LV, ie, "apical ballooning"; and (4) profound psychological stress (eg, death of relatives, domestic abuse, arguments, catastrophic medical diagnoses, devastating financial or gambling losses) immediately preceding and triggering the cardiac events. A significant proportion of patients (37%) had hemodynamic compromise and required vasopressor agents and intra-aortic balloon counterpulsation. Each patient survived with normalized ejection fraction (63+/-6%; P<0.001) and rapid restoration to previous functional cardiovascular status within 6+/-3 days. In 95%, MRI identified diffusely distributed segmental wall-motion abnormalities that encompassed LV myocardium in multiple coronary arterial vascular territories.

CONCLUSIONS

A reversible cardiomyopathy triggered by psychologically stressful events occurs in older women and may mimic evolving acute myocardial infarction or coronary syndrome. This condition is characterized by a distinctive form of systolic dysfunction that predominantly affects the distal LV chamber and a favorable outcome with appropriate medical therapy.

Neurohumoral features of myocardial stunning due to sudden emotional stress

BACKGROUND

Reversible left ventricular dysfunction precipitated by emotional stress has been reported, but the mechanism remains unknown.

METHODS

We evaluated 19 patients who presented with left ventricular dysfunction after sudden emotional stress. All patients underwent coronary angiography and serial echocardiography; five underwent endomyocardial biopsy. Plasma catecholamine levels in 13 patients with stress-related myocardial dysfunction were compared with those in 7 patients with Killip class III myocardial infarction.

RESULTS

The median age of patients with stress-induced cardiomyopathy was 63 years, and 95 percent were women. Clinical presentations included chest pain, pulmonary edema, and cardiogenic shock. Diffuse T-wave inversion and a prolonged QT interval occurred in most patients. Seventeen patients had mildly elevated serum troponin I levels, but only 1 of 19 had angiographic evidence of clinically significant coronary disease. Severe left ventricular dysfunction was present on admission (median ejection fraction, 0.20; interquartile range, 0.15 to 0.30) and rapidly resolved in all patients (ejection fraction at two to four weeks, 0.60; interquartile range, 0.55 to 0.65; P<0.001). Endomyocardial biopsy showed mononuclear infiltrates and contraction-band necrosis. Plasma catecholamine levels at presentation were markedly higher among patients with stress-induced cardiomyopathy than among those with Killip class III myocardial infarction (median epinephrine level, 1264 pg per milliliter [interquartile range, 916 to 1374] vs. 376 pg per milliliter [interquartile range, 275 to 476]; norepinephrine level, 2284 pg per milliliter [interquartile range, 1709 to 2910] vs. 1100 pg per milliliter [interquartile range, 914 to 1320]; and dopamine level, 111 pg per milliliter [interquartile range, 106 to 146] vs. 61 pg per milliliter [interquartile range, 46 to 77]; P<0.005 for all comparisons).

CONCLUSIONS

Emotional stress can precipitate severe, reversible left ventricular dysfunction in patients without coronary disease. Exaggerated sympathetic stimulation is probably central to the cause of this syndrome.

A modified and unifying neurogenic hypothesis can explain the natural history of chronic Chagas heart disease

The pathogenesis of chronic Chagas disease still is an unresolved and controversial issue. Parasite persistence and autoimmune responses cannot explain the spectrum of chronic Chagas disease. However, a modified neurogenic hypothesis, concerning the timing and mechanisms responsible for the cardiac parasympathetic damage and for the activation of the sympathetic nervous system and of other neurohormonal systems, unifies cardiac remodelling and neurohormonal activation to explain most of the events of the natural history of Chagas disease.

Blockade of β1- and desensitization of β2-adrenoceptors reduce isoprenaline-induced cardiac fibrosis

The aim of the present study was to analyse the role of beta(1)- and beta(2)-adrenoceptors in the catecholamine-induced myocardial remodeling, especially the interstitial fibrosis. Wistar rats were subjected to a 2-week chronic isoprenaline administration (30 microg/kg/h). Rats received a concomitant treatment with the selective beta(1)-adrenoceptor antagonist, bisoprolol (50 mg/kg/day p.o.) or were chronically pretreated with the selective beta(2)-adrenoceptor agonist salbutamol (40 microg/kg/h) for 1 week to induce beta(2)-adrenoceptor desensitization. The pretreatment with salbutamol induced a 59% down-regulation of left ventricular beta(2)-adrenoceptors compared to control. The extent of the isoprenaline-induced left ventricular fibrosis was significantly reduced in both the bisoprolol and salbutamol groups compared with the control isoprenaline-treated group especially in the apical region (1.7+/-0.6% and 1.4+/-0.3% versus 6.0+/-1.3%, respectively, P<0.005). beta(1)-adrenoceptor blockade and beta(2)-adrenoceptors down-regulation provided similar protection against isoprenaline-induced cardiac interstitial fibrosis suggesting that both beta-adrenoceptors are involved in such cardiac remodeling process.

Effect of intravenous propranolol on left ventricular apical ballooning without coronary artery stenosis (ampulla cardiomyopathy): three cases

The precise etiological basis of transient left ventricular apical ballooning without coronary artery stenosis (ampulla or so-called 'takotsubo' cardiomyopathy) remains unknown, so the present study examined the acute effects of intravenous propranolol (2-4 mg) in 3 female patients (age range, 61-76 years) with the condition. Although one patient who did not have any intraventricular pressure gradients showed no improvement in the electrocardiographic and left ventricular wall motion abnormalities, the other 2 patients, who had significant intraventricular pressure gradients, did show improvement. Dynamic intraventricular obstruction might play a role in maintaining apical ballooning, at least, in patients exhibiting an intraventricular pressure gradient.

Anteroapical stunning and left ventricular outflow tract obstruction

Dynamic left ventricular outflow tract (LVOT) obstruction is typically observed in the setting of hypertrophic cardiomyopathy. It has also been reported with concentric LV hypertrophy, excessive sympathetic stimulation, and acute myocardial infarction. We describe 3 patients with chest discomfort after emotional stress, who had pronounced abnormalities on electrocardiograms, insignificant obstructive coronary disease and hemodynamic instability with LVOT obstruction, and regional wall motion abnormalities. Suppression of contractility with beta-blockers resulted in resolution of the gradient and in clinical improvement. On follow-up, functional recovery was excellent, and ventricular function had normalized. The conditions and mechanisms that may produce this sequence of events are discussed. The most probable scenario is that an acute ischemic insult secondary to vasospasm, LV stunning, and acute geometric remodeling produced a substrate for LVOT obstruction that was exacerbated by basal LV hypercontractility. The importance of this observation is that routine treatment of cardiogenic shock cannot be used and that conservative management results in excellent prognosis.

The cardiac adrenergic system in ischaemia: differential role of acidosis and energy depletion

OBJECTIVE

Acute myocardial ischaemia has been shown to modulate the beta-adrenergic system and to activate protein kinase C. The aim of this study was to investigate if two important components of ischaemia, i.e. energy depletion or acidosis, may contribute to these changes.

METHODS

Isolated rat hearts were perfused either with anoxia (in the absence of oxygen) or with cyanide in the absence of glucose as models of energy depletion with a loss of high energy phosphates. Alternatively, isolated hearts were perfused with acidic modified Krebs-Henseleit solution to induce acidosis.

RESULTS

Energy depletion induced by cyanide perfusion leads to an increase of beta-adrenergic receptors (81 +/- 7 vs. 50 +/- 3 fmol/mg protein, p < or = 0.05) comparable to the changes observed in ischaemia, yet without any change of total adenylyl cyclase activity or protein kinase C activity. Similar, yet less pronounced changes were induced by anoxic perfusion. Acidic perfusion, in contrast, promotes a translocation of protein kinase C to the plasma membranes, suggesting its rapid activation. Additionally, an increased total forskolin-stimulated activity of adenylyl cyclase (515 +/- 16 vs. 428 +/- 17 pmol/min/mg, p < or = 0.05) was observed. Both were comparable to the sensitization observed in early ischaemia. In acidosis, the density of beta-adrenergic receptors remained unaltered.

CONCLUSIONS

These data suggest that the regulation of cardiac beta-adrenergic receptors is susceptible to energy depletion, but not to acidosis, whereas the intracellular enzymes both adenylyl cyclase and protein kinase C may be regulated by intracellular acidosis. This is the first differentiation of distinct components of ischaemia modulating the beta-adrenergic signal transduction pathway. Both components may be operative in concert in acute myocardial ischaemia and may contribute to the regulation of these components of signal transduction observed in acute ischaemia.

Microanalysis and distribution of cardiac troponin I phospho species in heart areas

Sequential phosphorylation and dephosphorylation of cTnI by the cAMP dependent protein kinase and by protein phosphatase 2A, respectively, produce the non-, mono- and bisphosphorylated species (Jaquet et al., 1995, Eur. J. Biochem. 231, 486-490). The aim of this study was to determine these forms even in small tissue samples, e.g. in biopsy probes of approximately 30 mg which would allow to define the phosphorylation state of cTnI in heart areas. In order to do so a micro isolation procedure for cTnI had to be established. cTnI is extracted from small bovine, rabbit and human heart tissue samples (30-100 mg) under special conditions avoiding dephosphorylation and is isolated by affinity chromatography on cTnC Sepharose. All three species, the bis-, mono- and dephospho cTnI, are precipitated quantitatively by acetone, then they are separated by non-equilibrium isoelectric focusing and quantified by scanning densitometry. The method presented here allows to quantify the three cTnI species reproducibly. No other phosphorylated species are detected. Truncated cTnI forms of each phospho species are found in human biopsy samples due to removal of a approximately 36 amino acid peptide from the C-terminus. In bovine, human and rabbit heart the pattern of the three cTnI phospho species is characteristic for left and right atrium, left and right ventricle and septum.

Local continuity of myocardial blood flow studied by monochromatic synchrotron radiation-excited x-ray fluorescence spectrometry

We have developed a monochromatic synchrotron radiation-excited system for two-dimensional mapping of x-ray fluorescence evoked from heavy element-loaded microspheres, which can evaluate myocardial blood flow in small contiguous regions with a small methodological error: 10.8 +/- 2.4% of the average of difference of the dual flow for 7- to 10-mg myocardial tissue (4 dogs). The fractal D value obtained from the slope of the log relative dispersion-log mass plot was 1.21 +/- 0.08 for a voxel size of 7 to 1260 mg (5 dogs) and that for a voxel size of 2.5 to 40 mg (1.12 +/- 0.06) was smaller than that for a voxel size of 40 to 1280 mg (1.25 +/- 0.14, P < .05, ANOVA, 4 dogs). The distance-correlation coefficient relation for paired myocardial regions was attenuated (correlation analysis), and the correlation coefficients between the original grouping and the two aggregates of the adjacent regions were dissociated (extended correlation analysis) under reduction of coronary perfusion pressure (6 dogs). Suppression of myocardial contraction with lidocaine (3 dogs) and vasodilation with adenosine partly improved the distance-correlation coefficient relation under reduced coronary perfusion pressure. Thus, an x-ray fluorescence system designed for precise flow measurement shows that the fractal nature of local flow distribution can be extended into regions smaller than previously reported, that in these regions the flow becomes more homogeneous, and that the self similarity and continuity of local flow are attenuated by the reduction of coronary perfusion pressure and improved by contractile suppression and coronary vasodilation.