Takotsubo cardiomyopathy: state-of-the-art review.

Takotsubo cardiomyopathy (TC) is characterized by transient, often severe, left ventricular dysfunction and electrocardiographic changes that might mimic acute myocardial infarction in the absence of significant obstructive coronary artery disease. It is often encountered in elderly women after physical or emotional stress. Excessive catecholamine stimulation, metabolic abnormalities, and microcirculatory dysfunction are thought to be responsible for the manifestations of this disorder. This comprehensive review summarizes relevant published data, atypical presentations, pathophysiology, and management strategy. It also includes a review of 789 patients with TC including nine illustrative cases encountered at our institution.

Regional pericarditis: a review of the pericardial manifestations of acute myocardial infarction.

Regional pericarditis has been described in several settings, but occurs most frequently after transmural myocardial infarction. While the diagnosis remains elusive, it must be considered in all patients with recurrent chest pain following acute myocardial infarction (AMI). Pericarditis classically presents with positional chest pain, a pericardial friction rub, diffuse ST-segment elevation, and PR depression, but regional ECG changes associated with infarction-associated pericarditis sometimes exist. Given the magnitude and frequency of AMI, it is imperative to be aware of the myriad of pericardial manifestations of myocardial injury. An illustrative case and a comprehensive review of the literature will be provided.

Diastolic suction is impaired by bed rest: MRI tagging studies of diastolic untwisting.

Bed rest deconditioning leads to physiological cardiac atrophy, which may compromise left ventricular (LV) filling during orthostatic stress by reducing diastolic untwisting and suction. To test this hypothesis, myocardial-tagged magnetic resonance imaging (MRI) was performed, and maximal untwisting rates of the endocardium, midwall, and epicardium were calculated by Harmonic Phase Analysis (HARP) before and after -6 degrees head-down tilt bed rest for 18 days with (n = 14) and without exercise training (n = 10). LV mass and LV end-diastolic volume were measured using cine MRI. Exercise subjects cycled on a supine ergometer for 30 min, three times per day at 75% maximal heart rate (HR). After sedentary bed rest, there was a significant reduction in maximal untwisting rates of the midwall (-46.8 +/- 14.3 to -35.4 +/- 12.4 degrees /s; P = 0.04) where untwisting is most reliably measured, and to a lesser degree of certainty in the endocardium (-50.3 +/- 13.8 to -40.1 +/- 18.5 degrees /s; P = 0.09); the epicardium was unchanged. In contrast, when exercise was performed in bed, untwisting rates were enhanced at the endocardium (-48.4 +/- 20.8 to -72.3 +/- 22.3 degrees /ms; P = 0.05) and midwall (-39.2 +/- 12.2 to -59.0 +/- 19.6 degrees /s; P = 0.03). The differential response was significant between groups at the endocardium (interaction P = 0.02) and the midwall (interaction P = 0.004). LV mass decreased in the sedentary group (156.4 +/- 30.3 to 149.5 +/- 27.9 g; P = 0.07), but it increased slightly in the exercise-trained subjects (156.4 +/- 34.3 to 162.3 +/- 40.5 g; P = 0.16); (interaction P = 0.03). We conclude that diastolic untwisting is impaired following sedentary bed rest. However, exercise training in bed can prevent the physiological cardiac remodeling associated with bed rest and preserve or even enhance diastolic suction.

An unusual manifestation of Takotsubo cardiomyopathy.

Takotsubo cardiomyopathy typically presents with chest pain, ST changes, and transient left ventricular apical ballooning in the absence of epicardial coronary artery disease. This process is reversible and usually benign. An unusual manifestation is that of left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve. Recognition of this finding is critical in patient management especially in the setting of cardiogenic shock, as inotropes are likely to aggravate and worsen the clinical condition. We provide a systematic review and an illustrative case and discuss treatment strategies.

Cardiac atrophy in women following bed rest.

Both chronic microgravity exposure and long-duration bed rest induce cardiac atrophy, which leads to reduced standing stroke volume and orthostatic intolerance. However, despite the fact that women appear to be more susceptible to postspaceflight presyncope and orthostatic hypotension than male astronauts, most previous high-resolution studies of cardiac morphology following microgravity have been performed only in men. Because female athletes have less physiological hypertrophy than male athletes, we reasoned that they also might have altered physiological cardiac atrophy after bed rest. Magnetic resonance imaging was performed in 24 healthy young women (32.1 +/- 4 yr) to measure left ventricular (LV) and right ventricular (RV) mass, volumes, and morphology accurately before and after 60 days of 6 degrees head-down tilt (HDT) bed rest. Subjects were matched and then randomly assigned to sedentary bed rest (controls, n = 8) or two treatment groups consisting of 1) exercise training using supine treadmill running within lower body negative pressure plus resistive training (n = 8), or 2) protein (0.45 g x kg(-1) x day(-1) increase) plus branched-chain amino acid (BCAA) (7.2 g/day) supplementation (n = 8). After sedentary bed rest without nutritional supplementation, there were significant reductions in LV (96 +/- 26 to 77 +/- 25 ml; P = 0.03) and RV volumes (104 +/- 33 to 86 +/- 25 ml; P = 0.02), LV (2.2 +/- 0.2 to 2.0 +/- 0.2 g/kg; P = 0.003) and RV masses (0.8 +/- 0.1 to 0.6 +/- 0.1 g/kg; P < 0.001), and the length of the major axis of the LV (90 +/- 6 to 84 +/- 7 mm. P < 0.001), similar to what has been observed previously in men (8.0%; Perhonen MA, Franco F, Lane LD, Buckey JC, Blomqvist Zerwekh JE, Peshock RM, Weatherall PT, Levine BD. J Appl Physiol 91: 645-653, 2001). In contrast, there were no significant reductions in LV or RV volumes in the exercise-trained group, and the length of the major axis was preserved. Moreover, there were significant increases in LV (1.9 +/- 0.4 to 2.3 +/- 0.3 g/kg; P < 0.001) and RV masses (0.7 +/- 0.1 to 0.8 +/- 0.2 g/kg; P = 0.002), as well as mean wall thickness (9 +/- 2 to 11 +/- 1 mm; P = 0.02). The interaction between sedentary and exercise LV and RV masses was highly significant (P < 0.0001). Protein and BCAA supplementation led to an intermediate phenotype with no change in LV or RV mass after bed rest, but there remained a significant reduction in LV volume (103 +/- 14 to 80 +/- 16 ml; P = 0.02) and major-axis length (91 +/- 5 to 88 +/- 7 mm; P = 0.003). All subjects lost an equivalent amount of body mass (3.4 +/- 0.2 kg control; 3.1 +/- 0.04 kg exercise; 2.8 +/- 0.1 kg protein). Cardiac atrophy occurs in women similar to men following sedentary 60 days HDT bed rest. However, exercise training and, to a lesser extent, protein supplementation may be potential countermeasures to the cardiac atrophy associated with chronic unloading conditions such as in spaceflight and prolonged bed rest.

Sarcoidosis masquerading as an acute coronary syndrome.

Sarcoidosis is a common multisystem granulomatous disease that affects 20 per 100,000 people in the world. Although primarily a pulmonary disease, sarcoidosis can affect multiple organ systems. Cardiac involvement of sarcoidosis is most commonly manifested as ventricular ectopy and arrhythmias; atrioventricular conduction disturbances, including complete heart block; congestive heart failure; and even may result in sudden death. Although myocardial infarction is most commonly the result of epicardial coronary artery disease, an infiltrative process such as sarcoidosis may simulate an acute coronary syndrome. Given the high prevalence of sarcoidosis, it is important to be aware of the myriad of cardiac manifestations of this infiltrative process.

Thrombotic occlusion of a large septal perforator presenting as ST-segment elevation in V1-V2 and treated with aspiration thrombectomy: a brief review of the literature.

The interventricular septum constitutes approximately one-third of the mass of the left ventricle, and the bulk of the anterior septum is supplied by septal branches of the left anterior descending coronary artery. Ischemia of the interventricular septum results in angina, infarction, biventricular failure and ventricular arrhythmias. While the majority of septal infarctions are due to occlusions of the proximal left anterior descending coronary artery, a large first septal branch thrombosis can rarely be the culprit. Given the paucity of data pertaining to septal perforator disease, a thorough discussion on septal perforator coronary artery interventions and an illustrative case will be provided.

Palliative combined percutaneous balloon aortic valvuloplasty and unprotected left main stenting in end stage renal disease.

With the aging population and high prevalence of atherosclerosis, an increasing number of patients presenting with heart failure and angina are found to have severe coronary artery disease and severe valvular disease. These patients tend to have multiple co-morbidities such as end stage renal disease and are considered high-risk for surgery. In patients with severe coronary artery disease, severe aortic stenosis, and heart failure with depressed left ventricular systolic function, the options are limited as they are not usually offered surgery, but palliative percutaneous high-risk procedures might be a viable alternative.Though long term results after balloon aortic valvuolpasty are not promising, there is a role for these procedures in high-risk inoperable patients for either palliation or as a bridge to surgery. Unprotected left main percutaneous interventions are also feasible with low complication rates. This review provides mounting evidence that it is reasonable to perform combined palliative balloon aortic valvuolpasty and high-risk coronary artery stenting in certain inoperable patients. An illustrative case is presented that extends the findings of the current literature and demonstrates that combined balloon aortic valvuolpasty and left main stenting could be a safe and effective alternative in the setting of heart failure, left ventricular dysfunction, and end stage renal disease.

The brain first or the heart: the approach to revascularizing severe co-existing carotid and coronary artery disease.

Combined symptomatic severe cerebralvascular disease and significant obstructive coronary artery disease frequently exist. For the past few decades, clinicians have debated the various treatment strategies for these high-risk patients including staged procedures and hybrid revascularization. While some recommend addressing the more unstable vascular territory first, others prefer to intervene on the carotids prior to performing coronary revascularization. Both surgical and percutaneous options have been explored in various clinical settings, but there are no treatment guidelines to date. Given the frequency and magnitude of this problem, we performed an extensive review of the literature in an attempt to add some much needed clarity. An illustrative case and recommendations are provided.

Relation between heart rate response to adenosine and mortality in patients with end-stage renal disease.

This study examined the relation between heart rate (HR) response to adenosine and outcome in patients with end-stage renal disease (ESRD). The usual HR increase during adenosine infusion was caused by direct sympathetic stimulation. It was hypothesized that a blunted HR response, which was probably caused by sympathetic denervation, would be associated with a worse outcome in patients with ESRD. One hundred thirty-nine patients with ESRD being evaluated for renal transplantation who underwent coronary angiography and adenosine gated single-photon emission computed tomographic myocardial perfusion imaging were followed up for all-cause mortality. Percentage of change in HR (%DeltaHR) was calculated as [(peak HR during adenosine infusion - HR at rest)/HR at rest] * 100. A control group of 54 patients (normal renal function and no diabetes) was included for comparison of HR responses. Mean age of patients was 54 +/- 9 years, 30% were women, and 68% had type-2 diabetes mellitus. %DeltaHR was 19.2 +/- 18% in patients with ESRD versus 33 +/- 25% in the control group (p <0.0001). At a mean follow-up of 3.4 +/- 1.5 years, 50 patients (36%) with ESRD died. %DeltaHR was lower in nonsurvivors than survivors (12.6 +/- 14% vs 23 +/- 19%; p = 0.0017). Patients with %DeltaHR less than the median value were more likely to have lower left ventricular ejection fraction and larger end-diastolic volume (p <0.05 for each). In a multivariate logistic regression model, %DeltaHR alone was an independent predictor of all-cause mortality (adjusted odds ratio 5.5, 95% confidence interval 2.3 to 12.9, p = 0.0001). In conclusion, patients with ESRD had a blunted HR response to adenosine, and degree of blunting was strongly associated with all-cause mortality.

The effects of medications on myocardial perfusion.

Antianginal and lipid-lowering medications may modify the results of stress myocardial perfusion imaging. Several studies have shown the beneficial potential of these agents in suppressing myocardial ischemia in patients with known coronary artery disease. The effects of nitrates, calcium-channel blockers, beta-blockers, and statins on myocardial perfusion imaging are likely attributable to changes in myocardial blood flow and myocardial oxygen supply-demand ratio. This comprehensive review examines relevant experimental and clinical published data. Technical issues in image interpretation specific to myocardial perfusion imaging and implications of use of cardiac medications to results of myocardial perfusion imaging are discussed.

Role of myocardial perfusion imaging in patients with end-stage renal disease undergoing coronary angiography.

Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. This study examined the prognostic power of stress myocardial perfusion imaging (MPI) in 150 patients with ESRD (mean age 53 +/- 9 years; 30% women; 66% with diabetes mellitus) being evaluated for renal transplantation with known coronary anatomy using angiography. Baseline data in addition to perfusion and angiographic parameters were compared between survivors and nonsurvivors. All-cause mortality was defined as the outcome measure. An abnormal MPI result was present in 85% of patients, 30% had left ventricular (LV) ejection fraction (EF) < or =40%, and 40% had multivessel coronary artery disease using angiography. At a mean follow-up of 3.4 +/- 1.5 years, 53 patients died (35%). LVEF < or =40%, LV dilatation (LV end-diastolic volume >90 ml), and diabetes mellitus were associated with higher mortality (all p <0.05). Both total perfusion defect size and mean number of narrowed coronary arteries using angiography were significantly higher in those who died (p <0.05). In a multivariate model, abnormal MPI results (low LVEF or abnormal perfusion) and diabetes alone were independent predictors of death, whereas number of narrowed arteries using coronary angiography was not. Thus, MPI was a strong predictor of all-cause mortality in patients with ESRD. In conclusion, abnormal MPI results independently predicted worse survival and provided more powerful prognostic data than coronary angiography.

Adenosine single photon emission computed tomography for assessing risk after myocardial infarction: recent developments.

PURPOSE OF REVIEW: While the prognostic power of adenosine single photon emission computed tomography myocardial perfusion imaging has been validated in multiple patient populations including those with known or suspected coronary artery disease, the utility of this modality in assessing risk after an acute myocardial infarction in the primary angioplasty era is still a topic of debate. RECENT FINDINGS: The INSPIRE trial showed that early adenosine single photon emission computed tomography myocardial perfusion imaging is capable of identifying low-risk patients for early hospital discharge after acute myocardial infarction. This novel study demonstrated that intensive medical therapy is a reasonable strategy in low, intermediate, and high-risk post-myocardial infarction patients with preserved left ventricular function. SUMMARY: The INSPIRE trial established the role for early adenosine single photon emission computed tomography myocardial perfusion imaging as a tool for risk stratification in stable patients after an acute myocardial infarction and provided evidence that intensive medical therapy is comparable to coronary revascularization in suppressing ischemia and presumably improving cardiac outcomes. It remains to be seen whether these new findings will alter current American College of Cardiology/American Heart Association guidelines, which emphasize a primary role of coronary revascularization in acute coronary syndromes.

Are emergency medical technician-basics able to use a selective immobilization of the cervical spine protocol?: a preliminary report.

OBJECTIVE: To be a first step in determining whether emergency medicine technician (EMT)-Basics are capable of using a protocol that allows for selective immobilization of the cervical spine. Such protocols are coming into use at an advanced life support level and could be beneficial when used by basic life support providers. METHOD: A convenience sample of participants (n=95) from 11 emergency medical services agencies and one college class participated in the study. All participants evaluated six patients in written scenarios and decided which should be placed into spinal precautions according to a selective spinal immobilization protocol. Systems without an existing selective spinal immobilization protocol received a one-hour continuing education lecture regarding the topic. College students received a similar lecture written so laypersons could understand the protocol. RESULTS: All participants showed proficiency when applying a selective immobilization protocol to patients in paper-based scenarios. Furthermore, EMT-Basics performed at the same level as paramedics when following the protocol. Statistical analysis revealed no significant differences between EMT-Basics and paramedics. A follow-up group of college students (added to have a non-EMS comparison group) also performed as well as paramedics when making decisions to use spinal precautions. Differences between college students and paramedics were also statistically insignificant. CONCLUSIONS: The results suggest that EMT-Basics are as accurate as paramedics when making decisions regarding selective immobilization of the cervical spine during paper-based scenarios. That laypersons are also proficient when using the protocol could indicate that it is extremely simple to follow. This study is a first step toward the necessary additional studies evaluating the efficacy of EMT-Basics using selective immobilization as a regular practice.