Diagnosis of acute myocardial infarction in patients with renal failure using high-sensitivity cardiac troponin T.

BACKGROUND: Diagnosing myocardial infarction (MI) in patients with chronic kidney disease (CKD) is difficult as they often have increased high-sensitivity cardiac troponin T (hs-cTnT) concentrations. METHODS: Observational U.S. cohort study of emergency department (ED) patients undergoing hs-cTnT measurement. Cases with >1 hs-cTnT increase >99th percentile were adjudicated following the Fourth Universal Definition of MI. Diagnostic performance of baseline and serial 2-hour hs-cTnT thresholds for ruling-in acute MI was compared between those without and with CKD (eGFR <60 ml/min/1.73m2). RESULTS: The study cohort included 1992 patients, amongst whom 501 (25%) had CKD. There were 75 (15%) and 350 (70%) patients with CKD and 80 (5%) and 351 (24%) without CKD who had acute MI and myocardial injury. In CKD patients with baseline hs-cTnT thresholds of >52, >100, >200 or >300 ng/L, PPVs for MI were 36% (95% CI 28-45), 53% (95% CI 39-67), 73% (95% CI 50-89) and 80% (95% CI 44-98), and in those without CKD, 61% (95% CI 47-73), 69% (95% CI 49-85), 59% (95% CI 33-82) and 54% (95% CI 25-81). In CKD patients with a 2-hour hs-cTnT delta of >10, >20 or >30 ng/L, PPVs were 66% (95% CI 51-79), 86% (95% CI 68-96) and 88% (95% CI 68-97), and in those without CKD, 64% (95% CI 50-76), 73% (95% CI 57-86) and 75% (95% CI 58-88). CONCLUSION: Diagnostic performance of standard baseline and serial 2-hour hs-cTnT thresholds to rule-in MI is suboptimal in CKD patients. It significantly improves when using higher baseline thresholds and delta values.

Contemporary Management of Pulmonary Embolism: Review of the Inferior Vena Cava filter and Other Endovascular Devices.

Inferior vena cava (IVC) filters and endovascular devices are used to mitigate the risk of pulmonary embolism in patients presenting with lower extremity venous thromboembolism in whom long-term anticoagulation is not a good option. However, the efficacy and benefit of these devices remain uncertain, and controversies exist. This review focuses on the current use of IVC filters and other endovascular therapies in clinical practice. The indications, risks, and benefits are discussed based on current data. Further research and randomized controlled trials are needed to characterize the patient population that would benefit most from these interventional therapies.

The Effects of Obstructive Sleep Apnea on the Cardiovascular System: A Comprehensive Review.

Obstructive sleep apnea (OSA) is an increasingly relevant cause of cardiovascular morbidity worldwide. Although the association between OSA and the cardiovascular system is well-known, the extent of its effects is still a topic of interest, including pathophysiologic mechanisms, cardiovascular sequelae, and OSA therapies and their effects. Commonly described mechanisms of cardiovascular etiologies revolve around sympathetic activation, inflammation, and intermittent hypoxia resulting from OSA. Ultimately, these effects lead to manifestations in the cardiovascular system, such as arrhythmias, hypertension, and heart failure, among others. The resulting sequelae of OSA may also have differential effects based on gender and age; several studies suggest female gender to have more susceptibility to cardiovascular mortality, as well as an increase in age. Furthermore, several therapies for OSA, both established and emerging, show a reduction in cardiovascular morbidity and may even reduce cardiovascular burden. Namely, the establishment of CPAP has led to improvement in hypertension and cardiac function in patients with heart failure and even reduced the progression of early stages of atherosclerosis. Effective management of OSA decreases abnormal neural sympathetic activity, which results in better rhythm control and blood pressure control, both in waking and sleep cycles. With newer therapies for OSA, its effects on the cardiovascular system may be significantly reduced or even reversed after long-term management. The vast extent of OSA on the cardiovascular system, as well as current and future therapeutic strategies, will be described in detail in this review.

Diagnosis and Prognosis of Type 2 Myocardial Infarction Using Objective Evidence of Acute Myocardial Ischemia: A Validation Study.

BACKGROUND: Differentiating type 2 myocardial infarction from myocardial injury can be difficult. In addition, the presence of objective evidence of myocardial ischemia may facilitate identification of high-risk type 2 myocardial infarction patients. METHODS: This was an observational cohort study of adult emergency department patients undergoing high-sensitivity cardiac troponin T (hs-cTnT) measurement. Patients with ≥1 hs-cTnT >99th percentile were adjudicated following the Fourth Universal Definition of Myocardial Infarction. Patients were categorized as "subjective type 2 myocardial infarction" when ischemic symptoms were the lone criteria supporting type 2 myocardial infarction, or "objective type 2 myocardial infarction" when there was ≥1 objective clinical feature (electrocardiography, imaging, angiography) of acute myocardial ischemia. The primary outcome was mortality. RESULTS: A total of 857 patients were included, among which 55 (6.4%) were classified as subjective type 2 myocardial infarction, 36 (4.2%) as objective type 2 myocardial infarction, and 702 (82%) as myocardial injury. Those with objective type 2 myocardial infarction had a higher risk of mortality during the index presentation (17% vs 1.7%, P < .0001; hazard ratio 11.1; 95% confidence interval, 3.7-33.4) and at 2-year follow-up (47% vs 31%, P = .04; hazard ratio 1.92; 95% confidence interval, 1.17-3.14) than those with myocardial injury. Objective type 2 myocardial infarction had a higher mortality than subjective type 2 myocardial infarction at index presentation (17% vs 2.0%, P = .01) and at 1 (25% vs 9.1%, P = .04) and 3 months (31% vs 13%, P = .04) follow-up. There were no mortality differences between subjective type 2 myocardial infarction and myocardial injury. CONCLUSION: In patients diagnosed with type 2 myocardial infarction, those with objective evidence of myocardial ischemia have significantly worse outcomes compared with those with myocardial injury and subjective type 2 myocardial infarction. A more rigorous type 2 myocardial infarction definition that emphasizes these criteria may facilitate diagnosis and risk-stratification.

Pathophysiology and Management of Pulmonary Embolism.

Pulmonary embolism (PE) is one of the most common etiologies of cardiovascular mortality. It could be linked to several risk factors including advanced age. The pathogenesis of PE is dictated by the Virchow's triad that includes venous stasis, endothelial injury, and a hypercoagulable state. The diagnosis of PE is difficult and is often missed due to the nonspecific symptomatology. Hypoxia is common in the setting of PE, and the degree of respiratory compromise is multifactorial and influenced by underlying cardiac function, clot location, and ability to compensate with respiratory mechanics. Right ventricular dysfunction/failure is the more profound cardiovascular impact of acute PE and occurs due to sudden increase in afterload. This is also the primary cause of death in PE. High clinical suspicion is required in those with risk factors and presenting signs or symptoms of venous thromboembolic disease, with validated clinical risk scores such as the Wells, Geneva, and pulmonary embolism rule out criteria in estimating the likelihood for PE. Advancement in capture time and wider availability of computed tomographic pulmonary angiography and D-dimer testing have further facilitated the rapid evaluation and diagnosis of suspected PE. Treatment is dependent on clinical presentation and initially involves providing adequate oxygenation and stabilizing hemodynamics. Anticoagulant therapy is indicated for the treatment of PE. Treatment is guided by presence or absence of shock and ranges from therapeutic anticoagulation to pharmacologic versus mechanical thrombectomy. The prognosis of patients can vary considerably depending on the cardiac and pulmonary status of patient and the size of the embolus.

Major adverse cardiovascular events after diagnosis of myocardial injury and types 1 and 2 myocardial infarction.

AIMS: Limited US outcome data exist among patients with myocardial injury and types 1 and 2 myocardial infarction (MI) evaluated with high-sensitivity cardiac troponin (hs-cTn). METHODS AND RESULTS: This is an observational US cohort study of emergency department (ED) patients undergoing hs-cTnT measurement. Cases with ≥1 hs-cTnT increase >99th percentile were adjudicated following the Fourth Universal Definition of MI. Post-discharge major adverse cardiovascular events (MACE) included death, MI, heart failure (HF) hospitalization, stroke or transient ischaemic attack, and new-onset atrial fibrillation or flutter during 2 years follow-up. Among 2002 patients, 857 (43%) had ≥1 hs-cTnT >99th percentile. Among these, 702 (81.9%) had myocardial injury, 64 (7.5%) had type 1 MI, and 91 (10.6%) had type 2 MI. Compared with patients without myocardial injury, type 2 MI [8.4 vs. 50%; adjusted hazard ratio (HR) 2.31, 95% confidence interval (CI) 1.49-3.58] and myocardial injury (8.4 vs. 47%; adjusted HR 3.13, 95% CI 2.39-4.09) had a higher risk of MACE, in large part because of death and HF hospitalizations. Compared with patients with type 1 MI, type 2 MI (23 vs. 50%; adjusted HR 2.24; 95% CI 1.23-4.10) and myocardial injury (23 vs. 47%; adjusted HR 2.02; 95% CI 1.20-3.40) also have a higher risk of MACE. CONCLUSION: Among unselected US ED patients undergoing hs-cTnT measurement, most increases are due to myocardial injury, and type 2 MI is more frequent than type 1 MI. Patients with myocardial injury and type 2 MI have morbid outcomes, in large part due to death and HF.

Rapid Exclusion of Acute Myocardial Injury and Infarction With a Single High-Sensitivity Cardiac Troponin T in the Emergency Department: A Multicenter United States Evaluation.

BACKGROUND: There are good data to support using a single high-sensitivity cardiac troponin T (hs-cTnT) below the limit of detection of 5 ng/L to exclude acute myocardial infarction. Per the US Food and Drug Administration, hs-cTnT can only report to the limit of quantitation of 6 ng/L, a threshold for which there are limited data. Our goal was to determine whether a single hs-cTnT below the limit of quantitation of 6 ng/L is a safe strategy to identify patients at low risk for acute myocardial injury and infarction. METHODS: The efficacy (proportion identified as low risk based on baseline hs-cTnT<6 ng/L) of identifying low-risk patients was examined in a multicenter (n=22 sites) US cohort study of emergency department patients undergoing at least 1 hs-cTnT (CV Data Mart Biomarker cohort). We then determined the performance of a single hs-cTnT<6 ng/L (biomarker alone) to exclude acute myocardial injury (subsequent hs-cTnT >99th percentile in those with an initial hs-cTnT<6 ng/L). The clinically intended rule-out strategy combining a nonischemic ECG with a baseline hs-cTnT<6 ng/L was subsequently tested in an adjudicated cohort in which the diagnostic performance for ruling out acute myocardial infarction and safety (myocardial infarction or death at 30 days) were evaluated. RESULTS: A total of 85 610 patients were evaluated in the CV Data Mart Biomarker cohort, among which 24 646 (29%) had a baseline hs-cTnT<6 ng/L. Women were more likely than men to have hs-cTnT<6 ng/L (38% versus 20%, P<0.0001). Among 11 962 patients with baseline hs-cTnT<6 ng/L and serial measurements, only 1.2% developed acute myocardial injury, resulting in a negative predictive value of 98.8% (95% CI, 98.6-99.0) and sensitivity of 99.6% (95% CI, 99.5-99.6). In the adjudicated cohort, a nonischemic ECG with hs-cTnT<6 ng/L identified 33% of patients (610/1849) as low risk and resulted in a negative predictive value and sensitivity of 100% and a 30-day rate of 0.2% for myocardial infarction or death. CONCLUSIONS: A single hs-cTnT below the limit of quantitation of 6 ng/L is a safe and rapid method to identify a substantial number of patients at very low risk for acute myocardial injury and infarction.

Clinical Impact of High-Sensitivity Cardiac Troponin T Implementation in the Community.

BACKGROUND: Limited U.S. data exist regarding high-sensitivity cardiac troponin (cTn) implementation. OBJECTIVES: This study sought to evaluate the impact of high-sensitivity cardiac troponin T (cTnT) implementation. METHODS: Observational U.S. cohort study of emergency department (ED) patients undergoing measurement of cTnT during the transition from 4th (pre-implementation March 12, 2018, to September 11, 2018) to 5th generation (Gen) cTnT (post-implementation September 12, 2018, to March 11, 2019). Diagnoses were adjudicated following the Fourth Universal Definition of Myocardial Infarction (MI). Resources evaluated included length of stay, hospitalizations, and cardiac testing. RESULTS: In this study, 3,536 unique patients were evaluated, including 2,069 and 2,491 ED encounters pre- and post-implementation. Compared with 4th Gen cTnT, encounters with ≥1 cTnT >99th percentile increased using 5th Gen cTnT (15% vs. 47%; p < 0.0001). Acute MI (3.3% vs. 8.1%; p < 0.0001) and myocardial injury (11% vs. 38%; p < 0.0001) increased. Although type 1 MIs increased (1.7% vs. 2.9%; p = 0.0097), the overall MI increase was largely due to more type 2 MIs (1.6% vs. 5.2%; p < 0.0001). Women were less likely than men to have MI using 4th Gen cTnT (2.3% vs. 4.4%; p = 0.008) but not 5th Gen cTnT (7.7% vs. 8.5%; p = 0.46). Overall length of stay and stress testing were reduced, and angiography was increased (all p < 0.05). Among those without cTnT increases, there were more ED discharges and a reduction in length of stay, echocardiography, and stress tests (all p < 0.05). CONCLUSIONS: High-sensitivity cTnT implementation resulted in a marked increase in myocardial injury and MI, particularly in women and patients with type 2 MI. Despite this, except for angiography, overall resource use did not increase. Among those without cTnT increases, there were more ED discharges and fewer cardiac tests.

l -Arginine Can Enhance the Beneficial Effect of Losartan in Patients with Chronic Aortic Regurgitation and Isolated Systolic Hypertension.

Information about the effects of angiotensin II receptor blocker (ARB) therapy on the hemodynamic and cardiac structure in patients with chronic aortic regurgitation (CAR) and isolated systolic hypertension (ISH) is limited. This study planned to test the hypothesis that l -arginine could further enhance the beneficial effect of an ARB, losartan, and provide a favorable effect on the natural history of CAR and ISH. Sixty patients with CAR and ISH were enrolled in a randomized, double-blind trial comparing hemodynamic and ultrasonic change in two treatment arms: losartan + l -arginine and losartan-only treated groups. Serial echocardiographic and hemodynamic studies were evaluated before and after treatment. Both groups had a significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), left ventricular end-diastolic volume index (LVEDVI), LV end-systolic volume index (LVESVI), LV mass index (LVMI), and LV mean wall stress after 6- and 12-month treatment ( p <0.01 in all comparisons). Both groups had a significant increase in LV ejection fraction and exercise duration after 6- and 12-month treatment ( p < 0.01 in all comparisons). Using multivariate linear regression analysis, only losartan + l -arginine therapy achieved a significantly lower LVESVI (38.89 ± 0.23 mL/m 2 ), LVEDVI (102.3 ± 0.3 mL/m 2 ), LVMI (107.6 ± 0.3 g/m 2 ), SBP (123.5 ± 1.0 mm Hg), and greater exercise duration (7.38 ± 0.02 minutes) than those of the losartan-only treated groups ( p <0.01 in all comparisons). These findings suggest that early co-administrative strategy provides a beneficial approach to favorably influence the natural history of CAR.

Management of ST-Elevation Myocardial Infarction in High-Risk Settings.

Despite the widespread adoption of primary percutaneous intervention and modern antithrombotic therapy, ST-segment elevation myocardial infarction (STEMI) remains the leading cause of death in the United States and remains one of the most important causes of morbidity and mortality worldwide. Certain high-risk patients present a challenge for diagnosis and treatment. The widespread adoption of primary percutaneous intervention in addition to modern antithrombotic therapy has resulted in substantial improvement in the short- and long-term prognosis following STEMI. In this review, we aim to provide a brief analysis of the state-of-the-art treatment for patients presenting with STEMI, focusing on cardiogenic shock, current treatment and controversies, cardiac arrest, and diagnosis and treatment of mechanical complications, as well as multivessel and left main-related STEMI.

Measurement of Ejection Fraction by Cardiac Magnetic Resonance Imaging and Echocardiography to Monitor Doxorubicin-Induced Cardiotoxicity.

Doxorubicin is a standard treatment option for breast cancer, lymphoma, and leukemia, but its benefits are limited by its potential for cardiotoxicity. The primary objective of this study was to compare cardiac magnetic resonance imaging (CMRI) versus echocardiography (ECHO) to detect a reduction in left ventricular ejection function, suggestive of doxorubicin cardiotoxicity. We studied eligible patients who were 18 years or older, who had breast cancer or lymphoma, and who were offered treatment with doxorubicin with curative intent dosing of 240 to 300 mg/m 2 body surface area between March 1, 2009 and October 31, 2013. Patients underwent baseline CMRI and ECHO. Both imaging studies were repeated after four cycles of treatment. Ejection fraction (EF) calculated by both methods was compared and analyzed with the inferential statistical Student's t test. Twenty-eight eligible patients were enrolled. Two patients stopped participating in the study before undergoing baseline CMRI; 26 patients underwent baseline ECHO and CMRI. Eight of those 26 patients declined posttreatment studies, so the final study population was 18 patients. There was a significant difference in EF pre- and posttreatment in the CMRI group ( p = 0.009) versus the ECHO group that showed no significant differences in EF ( p = NS). It appears that CMRI is superior to ECHO for detecting doxorubicin-induced reductions in cardiac systolic function. However, ECHO is less expensive and more convenient for patients because of its noninvasive character and bedside practicality. A larger study is needed to confirm these findings.

Acute Pulmonary Embolism: Contemporary Approach to Diagnosis, Risk-Stratification, and Management.

Pulmonary embolism (PE) affects over 300,000 individuals each year in the United States and is associated with substantial morbidity and mortality. Improvements in the diagnostic performance and availability of computed tomographic pulmonary angiography and D-dimer testing have facilitated the evaluation of patients with suspected PE. High clinical suspicion is required in those with risk factors and/or those that manifest signs or symptoms of venous thromboembolic disease, with validated clinical risk scores such as the Wells and modified Wells score or the PE rule-out criteria helpful in estimating the likelihood for PE. For those with confirmed PE, patients should be categorized and triaged according to the presence or absence of shock or hypotension. Normotensive patients can be further risk-stratified using validated prognostic risk scores, as well as by using imaging and cardiac biomarkers, with those having either signs of right ventricular dysfunction on imaging studies and/or abnormal cardiac biomarkers categorized as being at intermediate-risk and requiring close monitoring and hospital admission. Early discharge and/or home therapy are possible in those that do not manifest any high-risk features. The initial treatment for most patients that are stable consists of anticoagulation, with advanced therapies such as thrombolysis, catheter-based therapies, or surgical embolectomy deferred for those at high risk. Given the heterogeneous presentations of PE and various management strategies available, the development of multidisciplinary PE response teams has emerged to help facilitate decision-making in these patients.

Pseudo-Wellens Syndrome in a Patient with Hypertension and Left Ventricular Hypertrophy.

BACKGROUND Wellens syndrome is a form of unstable angina that warrants a timely intervention to prevent extensive myocardial infarction. A few conditions can lead to electrocardiogram (EKG) changes mimicking Wellens syndrome. CASE REPORT A 61-year-old African American man with no significant medical history was admitted for chest pain and new biphasic EKG changes in leads V2 through V6 concerning for Wellens' syndrome. He was found to have hypertension during his hospitalization and had left ventricular hypertrophy by echocardiogram. He was urgently evaluated with a cardiac catheterization, which demonstrated a normal coronary artery anatomy. The patient was diagnosed with pseudo-Wellens syndrome. CONCLUSIONS LVH secondary to hypertension could mimic Wellens syndrome and should be considered when evaluating patients with anterior T wave abnormalities on electrocardiograms. In patients who do not have acute coronary syndrome and in whom the T wave abnormalities are not classic for Wellens-type changes, non-invasive imaging instead of cardiac catheterization may be indicated initially.

Familial Tako-tsubo Cardiomyopathy: Clinical and Echocardiographic Features Including Magnetic Resonance Imaging Findings.

INTRODUCTION: Tako-tsubo cardiomyopathy (TCM) is being recognized more frequently; and a familial form of this diagnosis has been suspected but is less well-established. CASE: A 75-year-old patient with a family history of TCM was admitted with suspected ST-segment elevation myocardial infarction. Transthoracic echocardiography showed apical dyskinesis with hyperdynamic basal walls and a left ventricular ejection fraction (LVEF) of 25%. Repeat echocardiography showed normal LVEF of 60% ejection fraction. Cardiac catheterization showed no significant stenosis. DISCUSSION: TCM is characterized by transient systolic left ventricular dysfunction. A few cases of familial TCM have been reported in the literature and a genetic component is suspected. CONCLUSIONS: Although there has been a paucity of data, familial cases of TCM have been reported. This case study addresses TCM and the familial occurrence of the syndrome, which may have a genetic basis.

Relation of Activated Clotting Times During Percutaneous Coronary Intervention to Outcomes.

Monitoring anticoagulation using the activated clotting time (ACT) in patients treated with heparin and undergoing percutaneous coronary intervention (PCI) is one of the most frequently used tests in invasive cardiology. However, despite its widespread use and guideline endorsement, uncertainty remains regarding the association of ACT with outcomes in contemporary practice. We reviewed all PCI procedures performed at the Mayo Clinic (Rochester, Minnesota) from October 2001 to December 2012 and evaluated the association between the ACT before device activation and in-hospital and 1-year outcomes. ACT values were grouped into tertiles for descriptive purposes and analyzed as a continuous variable for assessment of outcomes. We used logistic and Cox proportional hazards regression models to estimate the association of ACT and outcomes. Of the 12,055 patients who underwent PCI with an ACT value before device activation, 3,977 (33.0%) had an ACT <227, 4,046 (33.6%) had an ACT 227 to 285, and 4,032 (33.4%) had an ACT >285. Baseline and procedural characteristics were similar across ACT tertiles. In unadjusted analysis, higher ACT values were associated with death (p <0.001), bleeding (p = 0.024), procedural complication (p <0.001), and higher 1-year events (cardiac death, p <0.001; cardiac death/myocardial infarction, p = 0.022). After multivariable adjustment for baseline and procedural characteristics, ACT was not independently associated with in-hospital or 1-year ischemic, thrombotic, or bleeding outcomes. In conclusion, ACT values before device activation are not independently associated with clinically important outcomes in contemporary PCI practice.

Effect of aging on human circulatory system in normotensive healthy subjects.

Aging is associated with degenerative changes in cardiac and endothelial function (EF). This study was done to assess whether age-related changes take place on EF, carotid intima-media thickness (IMT), blood pressure (BP), and echocardiographic measurements. All volunteers were healthy normotensive healthy subjects. They were divided into three groups. Group 1, young adults: < 40 years old; Group 2, middle age: between 40 and 60 years old; Group 3, elderly: > 60 years old. High-frequency vascular ultrasound was used to assess the baseline brachial artery dimension and flow velocity after reactive hyperemia. The carotid IMT and echocardiographic measurements including Doppler variables were recorded in all subjects. Systolic BP, left ventricular mass, and left ventricular end-diastolic volume increased progressively with age (p < 0.001). Left ventricular ejection fraction decreased progressively with age (male, p = 0.034; female, p = 0.001); E/A ratio of the left ventricular flow spectrum declined with age (p < 0.001). The ultrasonic EF variables of flow increased during reactive hyperemia and IMT increased with age (p < 0.001). Our study demonstrates that BP, body weight, and ultrasonic variables changed significantly with age. The aging-associated changes provide insight into progression to atherosclerosis.

Diagnosis of coronary artery fistulas: clinical aspects and brief review of the literature.

An 86-year-old woman with history of hypertension, diabetes, hyperlipidemia, and coronary artery disease was admitted with new-onset congestive heart failure and pneumonia. She underwent coronary angiography after suffering a non-ST elevation myocardial infarction. There was severe coronary artery disease in addition to coronary artery-pulmonary fistulas involving proximal right coronary artery and a branch of left main coronary artery. Coronary artery fistula (CAF) is an abnormal communication between one or more coronary arteries and great vessels or a cardiac chamber. We reviewed 15 cases of CAFs published in PubMed and studied the clinical features of CAFs.

The role of enhanced external counter pulsation therapy in clinical practice.

Enhanced external counterpulsation (EECP) has been approved by the United States Food and Drug Administration (FDA) for management of refractory angina (Class IIb). EECP uses three sets of pneumatic cuffs that sequentially contract during diastole, increasing aortic diastolic pressure, augmenting coronary blood flow and central venous return. EECP improves anginal symptoms and exercise tolerance, and reduces nitroglycerin use in patients with chronic, stable angina. EECP has also been shown to be safe and beneficial in patients with symptomatic stable congestive heart failure. It has been postulated that cardiac benefits of EECP are mediated though vascular endothelial growth factor (VEGF) and nitric oxide mediated vasodilatation and angiogenesis. In June 2002, the FDA also approved EECP therapy for heart failure patients.

A case of supraventricular tachycardia associated with Wolff-Parkinson-White syndrome and pregnancy.

A 25-year-old pregnant woman was admitted with frequent episodes of supraventricular tachycardia associated with Wolf-Parkinson-White syndrome. She was treated acutely with adenosine therapy during induction of labor and post-partum. Generally, pharmacologic treatment should be undertaken only for symptomatic arrhythmias or in hemodynamically compromised patients. Adenosine is the first choice for acute treatment of supraventricular tachycardia in pregnancy; several other options exist, but all have the potential for negative side effects for mother and fetus. Direct-current cardioversion is acceptable in all stages of pregnancy.

Obstructive sleep apnea and cardiovascular disease.

Obstructive sleep apnea (OSA) is a sleep-disordered breathing condition, which is increasingly being recognized as having wide-ranging pathophysiological effects on multiple organ systems. Although multiple factors affect the incidence and severity of OSA, male sex and obesity seem to play an influential role. The apnea-ventilation cycle, characterized by abnormalities in gas exchange, exaggerated respiratory effort and frequent arousals, has been shown to have deleterious effects on circulatory hemodynamics, the autonomic milieu, hormonal balance, inflammatory and coagulation cascades, endothelial function, and the redox state, with potential cardiovascular significance. Consequently, OSA is being increasingly implicated in a multitude of cardiovascular diseases (CVD) such as hypertension, congestive heart failure, atrial fibrillation, stroke, coronary artery disease, pulmonary hypertension, and metabolic syndrome. The strength of association for individual CVD is varied, and outcomes of clinical studies are conflicting. In addition, obesity, which is closely linked to both OSA and CVD, makes it harder to ascertain the independent role of OSA on CVD. Although available evidence is inconclusive, there is an increasing recognition of the direct role for OSA in CVD. Similarly, although several studies have demonstrated the cardiovascular benefits of OSA treatment, further studies are needed to confirm this.