Takotsubo Syndrome: Pathophysiology, Emerging Concepts, and Clinical Implications.

Takotsubo syndrome is a condition characterized by acute transient left ventricular systolic dysfunction, which at presentation can be challenging to distinguish from acute myocardial infarction. Although previously thought to be a benign, self-limiting condition, recent studies have confirmed that patients with takotsubo syndrome have persistent subtle ongoing cardiac dysfunction, and many continue to have limiting symptoms despite restoration of left ventricular ejection fraction. Moreover, these patients have a substantial burden of morbidity and mortality, as well, with high rates of subsequent major adverse cardiovascular events that approach those of patients with acute coronary syndrome. The mechanisms behind this condition remain elusive. Despite substantial research, the medical community continues to have an incomplete understanding of its underlying pathogenesis and pathophysiology. Catecholamine-induced myocardial injury is the most established and well-known theory, but this does not explain all the clinical features and presentations of the condition, and numerous other pathways and abnormalities are emerging. Because of the poor understanding of its underlying pathophysiology, there is a lack of evidence-based interventions to treat the acute episode, to avoid recurrences, and to prevent major adverse cardiovascular events. This highlights the need for further research to gain a better understanding of the underlying pathophysiology to inform appropriate randomized controlled trials of interventions targeting the causative pathways. Only then can evidence-based management strategies be established to improve clinical outcomes of this potentially lethal condition.

The early dynamic of ECG in Takotsubo syndrome presenting with ST-elevation: A comparison with age and gender-matched ST-elevation myocardial infarction.

BACKGROUND: Takotsubo syndrome mimics acute myocardial infarction (MI) at presentation. OBJECTIVES: To explore differences in ECG time-course that could further help distinguish the two conditions. METHODS: Serial ECG's (day 0-4) of 27 acute takotsubo and 37 MI patients, all presenting with anterior ST-elevation, were analysed for detailed morphology and timing of de/re-polarisation. All underwent cardiac magnetic resonance. RESULTS: The presenting ECG (day 0) showed significantly fewer total abnormal leads (p = .001), comparable number of ST-elevation leads but lesser total magnitude of ST-elevation (p = .003), smaller sum of positive T wave amplitude (p = .006) and lesser number of pathological Q waves (p = .005) in takotsubo vs the MI group. After day 0, takotsubo patients developed more widespread T wave inversion (p = .001, day 3) and/or deeper T waves compared to MI, (sum of the T-wave amplitude slope of change between days 0-3: -43.1 ± 9.6 vs - 16.6 ± 5.4 mm, p = .02). Although there was no difference in mean QTc between the groups on any day, between days 0-3 there was a progressive increase in QTc in takotsubo vs a decrease in MI (34.1 ± 12.2 vs -29.5 ± 9.3 ms, slope of change p < .001). There was significantly more myocardial oedema (native T1 mapping) in takotsubo vs MI (p = .02), which resulted in increased left ventricular mass index in takostubo (p = .04). CONCLUSIONS: The differences in presenting (day 0) ECG between takotsubo and MI are significant but subtle, reinforcing the importance of acute cardiac catheterisation for accurate diagnosis. During the next 3 days there is progressive increase in the depth and spread of T-waves and QTc duration in takotsubo vs MI - these may aid the diagnostic confidence in patients with bystander non-obstructive coronary disease.

Myocardial and Systemic Inflammation in Acute Stress-Induced (Takotsubo) Cardiomyopathy.

BACKGROUND: Acute stress-induced (takotsubo) cardiomyopathy can result in a heart failure phenotype with a prognosis comparable with that of myocardial infarction. In this study, we hypothesized that inflammation is central to the pathophysiology and natural history of takotsubo cardiomyopathy. METHODS: In a multicenter study, we prospectively recruited 55 patients with takotsubo cardiomyopathy and 51 age-, sex-, and comorbidity-matched control subjects. During the index event and at the 5-month follow-up, patients with takotsubo cardiomyopathy underwent multiparametric cardiac magnetic resonance imaging, including ultrasmall superparamagnetic particles of iron oxide (USPIO) enhancement for detection of inflammatory macrophages in the myocardium. Blood monocyte subpopulations and serum cytokines were assessed as measures of systemic inflammation. Matched control subjects underwent investigation at a single time point. RESULTS: Subjects were predominantly middle-aged (64±14 years) women (90%). Compared with control subjects, patients with takotsubo cardiomyopathy had greater USPIO enhancement (expressed as the difference between pre-USPIO and post-USPIO T2*) in both ballooning (14.3±0.6 milliseconds versus 10.5±0.9 milliseconds; P<0.001) and nonballooning (12.9±0.6 milliseconds versus 10.5±0.9 milliseconds; P=0.02) left ventricular myocardial segments. Serum interleukin-6 (23.1±4.5 pg/mL versus 6.5±5.8 pg/mL; P<0.001) and chemokine (C-X-C motif) ligand 1 (1903±168 pg/mL versus 1272±177 pg/mL; P=0.01) concentrations and classic CD14++CD16- monocytes (90±0.5% versus 87±0.9%; P=0.01) were also increased whereas intermediate CD14++CD16+ (5.4±0.3% versus 6.9±0.6%; P=0.01) and nonclassic CD14+CD16++ (2.7±0.3% versus 4.2±0.5%; P=0.006) monocytes were reduced in patients with takotsubo cardiomyopathy. At 5 months, USPIO enhancement was no longer detectable in the left ventricular myocardium, although persistent elevations in serum interleukin-6 concentrations ( P=0.009) and reductions in intermediate CD14++CD16+ monocytes (5.6±0.4% versus 6.9±0.6%; P=0.01) remained. CONCLUSIONS: We demonstrate for the first time that takotsubo cardiomyopathy is characterized by a myocardial macrophage inflammatory infiltrate, changes in the distribution of monocyte subsets, and an increase in systemic proinflammatory cytokines. Many of these changes persisted for at least 5 months, suggesting a low-grade chronic inflammatory state. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02897739.

Persistent Long-Term Structural, Functional, and Metabolic Changes After Stress-Induced (Takotsubo) Cardiomyopathy.

BACKGROUND: Takotsubo cardiomyopathy is an increasingly recognized acute heart failure syndrome precipitated by intense emotional stress. Although there is an apparent rapid and spontaneous recovery of left ventricular ejection fraction, the long-term clinical and functional consequences of takotsubo cardiomyopathy are ill-defined. METHODS: In an observational case-control study, we recruited 37 patients with prior (>12-month) takotsubo cardiomyopathy, and 37 age-, sex-, and comorbidity-matched control subjects. Patients completed the Minnesota Living with Heart Failure Questionnaire. All participants underwent detailed clinical phenotypic characterization, including serum biomarker analysis, cardiopulmonary exercise testing, echocardiography, and cardiac magnetic resonance including cardiac 31P-spectroscopy. RESULTS: Participants were predominantly middle-age (64±11 years) women (97%). Although takotsubo cardiomyopathy occurred 20 (range 13-39) months before the study, the majority (88%) of patients had persisting symptoms compatible with heart failure (median of 13 [range 0-76] in the Minnesota Living with Heart Failure Questionnaire) and cardiac limitation on exercise testing (reduced peak oxygen consumption, 24±1.3 versus 31±1.3 mL/kg/min, P<0.001; increased VE/Vco2 slope, 31±1 versus 26±1, P=0.002). Despite normal left ventricular ejection fraction and serum biomarkers, patients with prior takotsubo cardiomyopathy had impaired cardiac deformation indices (reduced apical circumferential strain, -16±1.0 versus -23±1.5%, P<0.001; global longitudinal strain, -17±1 versus -20±1%, P=0.006), increased native T1 mapping values (1264±10 versus 1184±10 ms, P<0.001), and impaired cardiac energetic status (phosphocreatine/γ-adenosine triphosphate ratio, 1.3±0.1 versus 1.9±0.1, P<0.001). CONCLUSIONS: In contrast to previous perceptions, takotsubo cardiomyopathy has long-lasting clinical consequences, including demonstrable symptomatic and functional impairment associated with persistent subclinical cardiac dysfunction. Taken together our findings demonstrate that after takotsubo cardiomyopathy, patients develop a persistent, long-term heart failure phenotype. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02989454.

Alterations in Cardiac Deformation, Timing of Contraction and Relaxation, and Early Myocardial Fibrosis Accompany the Apparent Recovery of Acute Stress-Induced (Takotsubo) Cardiomyopathy: An End to the Concept of Transience.

BACKGROUND: Takotsubo syndrome is an increasingly recognized cause of chest pain and occasionally of cardiogenic shock. Despite rapid improvement of the left ventricular (LV) ejection fraction, recent registry data raise concerns about long-term prognosis. The aim of this study was to test the hypothesis that restoration of normal ejection fraction after acute takotsubo syndrome is not equivalent to full functional recovery. METHODS: Fifty-two patients with takotsubo syndrome (according to the Mayo Clinic criteria plus cardiac magnetic resonance imaging to exclude myocardial infarction) and 44 healthy control subjects of the same age, gender, and cardiovascular comorbidity distribution were prospectively recruited. The focus of the investigation was on patients with takotsubo syndrome presenting with ST-segment elevation-type electrocardiographic findings or malignant arrhythmias and with LV apical ballooning variant, and a 4-month recovery endpoint was assessed. Patients underwent echocardiographic assessment of LV myocardial deformation (global longitudinal, radial, and circumferential strain; LV twist, torsion, and untwist; and time to peak twist and untwist) and assessment of LV myocardial structure by pre- and post-contrast-enhanced cardiac magnetic resonance by T1 mapping acutely and at 4-month follow-up. Control subjects underwent a single-time-point investigation. Data were analyzed using paired or unpaired tests, as appropriate for their distribution, and corrected for multiple comparisons. RESULTS: The patients' mean age was 66 years (range, 28-87 years), and 92% were women. All abnormal echocardiographic indices observed acutely in patients with takotsubo syndrome improved (but did not necessarily normalize) at follow-up. Significant mechanotemporal alterations characterizing both systole (global longitudinal strain and apical circumferential strain, P < .01 for both; LV twist, twist rate, and torsion, P < .0001 for all) and diastole (untwist rate and time to peak untwisting, P < .001 for both) persisted at 4-month follow-up compared with control subjects, despite normalization of LV ejection fraction and volumes. Although native T1 (which demonstrates edema) normalized at 4-months follow-up only in segments contracting normally during the acute phase (T1 = 1,180 ± 40.6 msec [normally contracting segments, P = .20 vs control value of 1,189 ± 16 msec] and T1 = 1,208 ± 60.3 msec [dysfunctional segments, P < .05 vs control]), the extracellular volume fraction (which demonstrates diffuse fibrosis) remained significantly abnormal in all LV segments (whether normally contracting [0.328 ± 0.043, P < .001] or ballooning during acute presentation [0.320 ± 0.044, P < .001], both vs control value of 0.273 ± 0.045). CONCLUSIONS: In patients with the most clinically severe spectrum of takotsubo cardiomyopathy, regional LV systolic and diastolic deformation abnormalities persist beyond the acute event, despite normalization of global LV ejection fraction and size. In addition, although myocardial edema partly subsides, a process of global microscopic fibrosis develops in its place, detected as early as 4 months.

Takotsubo cardiomyopathy with severe bradyarrhythmia following epidural insertion.

We present a case of takotsubo cardiomyopathy (TTC) with ventricular stand still and atrioventricular block. TTC can mimic ST elevation myocardial infarction and heart failure, but in this case resulted in a severe cardiac conduction disorder and ventricular standstill. This is a recognised but unusual presentation and serves as a lesson to those undertaking anaesthetics to be vigilant for TTC.

Right Ventricular Involvement and Recovery After Acute Stress-Induced (Tako-tsubo) Cardiomyopathy.

Acute stress-induced (Tako-tsubo) cardiomyopathy is an increasingly recognized but insufficiently characterized syndrome. Here, we investigate the pathophysiology of right ventricular (RV) involvement in Tako-tsubo and its recovery time course. We prospectively recruited 31 patients with Tako-tsubo with predominantly ST-elevation electrocardiogram and 18 controls of similar gender, age, and co-morbidity distribution. Patients underwent echocardiography and cardiac magnetic resonance (CMR) imaging on a 3T Philips scanner in the acute phase (day 0 to 3 after presentation) and at 4-months follow-up. Visually, echocardiography was able to identify only 52% of patients who showed RV wall motion abnormalities on CMR. Only CMR-derived RV ejection fraction (p = 0.01) and echocardiography-estimated pulmonary artery pressure (p = 0.01) identify RV functional involvement in the acute phase. Although RV ejection fraction normalizes in most patients by 4 months, acutely there is RV myocardial edema in both functioning and malfunctioning segments, as measured by prolonged native T1 mapping (p = 0.02 for both vs controls), and this persists at 4 months in the acutely malfunctioning segments (p = 0.002 vs controls). The extracellular volume fraction was significantly increased acutely in all RV segments and remained increased at follow-up compared with controls (p = 0.004 for all). In conclusion, in a Tako-tsubo population presenting predominantly with ST-elevation electrocardiogram, we demonstrate that although RV functional involvement is seen in only half of the patients, RV myocardial edema is present acutely throughout the RV myocardium in all patients and results in microscopic fibrosis at 4-month follow-up.

Voltage-gated potassium channel antibody-related encephalopathy: a case which may extend the documented phenotype of this condition.

A 51-year-old man presented with a focal epileptic, fluctuating encephalopathy. Antibodies to voltage-gated potassium channels (VGKC-Abs) were detected in his serum. Several features of this case were different from those previously reported in VGKC-Ab-associated encephalitis, illustrating that it may have a broader phenotype than previously documented. These features were: excess hepatic iron deposits without cirrhosis, reduced consciousness and fluctuating neurological signs. Previous history included personality change, depression, type 2 diabetes mellitus, pupil sparing third nerve palsy and epilepsy secondary to a head injury. He had never drunk alcohol and had recovered from a similar episode 4 years previously. Both episodes resolved after approximately 2 months. The cerebrospinal fluid had a raised protein content but no organisms. The patient was heterozygous for C282Y and negative for H63D mutations excluding classical idiopathic haemochromatosis. He recovered with supportive care to his premorbid level of health.

Right ventricular dilation on CT pulmonary angiogram independently predicts mortality in pulmonary embolism.

BACKGROUND: The aim of this study was to determine the prognostic significance of right ventricular dilation on CT pulmonary angiogram in acute pulmonary embolism and to distinguish if this feature predicts mortality independently of the Pulmonary Embolism Severity Index, an established admission severity score. METHODS: A retrospective study of patients admitted with pulmonary embolism confirmed by CT pulmonary angiogram to three teaching hospitals in East Scotland between January 2005 and July 2007. Two radiologists judged presence of right ventricular dilation on CT pulmonary angiogram independently. The outcome of interest was 30 day mortality. Multivariable logistic regression was used to compare this outcome in patients with right ventricular dilation compared to those without right ventricular dilation, adjusting for Pulmonary Embolism Severity Index score. RESULTS: There were 585 patients included and 30.4% had right ventricular dilation on CT pulmonary angiogram. Patients with right ventricular dilation had increased 30 day mortality rates compared to patients without right ventricular dilation (12.4% vs. 5.4%; p=0.006). Survival analysis showed that a significantly greater proportion of deaths in the right ventricular dilation group occurred within the first 48h after admission compared to the group without right ventricular dilation (45.5% deaths vs. 9.1%; p=0.016). On multivariable analysis, adjusting for Pulmonary Embolism Severity Index score, right ventricular dilation was independently associated with increased 30 day mortality (OR 2.98; 95% CI 1.54-5.75; p=0.001). CONCLUSION: Right ventricular dilation on CT pulmonary angiogram is an independent predictor of 30 day mortality in acute pulmonary embolism.

Admission D-dimer can identify low-risk patients with community-acquired pneumonia.

STUDY OBJECTIVE: Severity assessment is an important component of the management of community-acquired pneumonia. Clinicians are increasingly searching for biomarkers to aid in clinical decisions. Coagulation disorders can accompany severe pneumonia. We seek to investigate the association of D-dimer, a fibrinolysis biomarker, and 30-day mortality or the need for mechanical ventilation or vasopressor support in emergency department (ED) patients with community-acquired pneumonia. METHODS: We prospectively enrolled ED patients with community-acquired pneumonia between December 2005 and January 2008 in a convenience manner. We measured D-dimer level with the Vitek ImmunoDiagnostic Assay System. To assess clinical illness severity, both CURB65 and the Pneumonia Severity Index (Pneumonia Severity Index class) were calculated. Our primary outcomes were 30-day mortality and need for mechanical ventilation or vasopressor support. RESULTS: Of the 314 enrolled patients, 23.9% of patients had a D-dimer level less than 500 ng/mL on initial ED measurement, and 81.3% of these patients were in Pneumonia Severity Index class I to III. A D-dimer level of less than 500 ng/mL had a negative likelihood ratio of 0 (95% confidence interval 0 to 1.37) for 30-day mortality and 0.33 (95% confidence interval 0.09 to 1.27) for need for mechanical ventilation or vasopressor support. For 30-day mortality, the area under the receiver operator characteristic curve for D-dimer was similar to both CURB65 and Pneumonia Severity Index class. For mechanical ventilation or vasopressor support, the area under the receiver operator characteristic curve for D-dimer was lower than that for CURB65 but did not differ from that for Pneumonia Severity Index. CONCLUSION: An admission D-dimer level less than 500 ng/mL is associated with low risk of short-term death and major morbidity in patients with community-acquired pneumonia.