Assessment of right ventricular reserve utilizing exercise provocation in systemic sclerosis.

Right ventricular (RV) capacity to adapt to increased afterload is the main determinant of outcome in pulmonary hypertension, a common morbidity seen in systemic sclerosis (SSc). We hypothesized that supine bicycle echocardiography (SBE), coupled with RV longitudinal systolic strain (RVLSS), improves detection of limitations in RV reserve in SSc. 56 SSc patients were prospectively studied during SBE with RV functional parameters compared at rest and peak stress. We further dichotomized patients based on resting RV systolic pressure (RVSP) to determine the effects of load on contractile response. Our pooled cohort analysis revealed reduced global RVLSS at rest (-16.2 ± 3.9%) with normal basal contractility (-25.6 ± 7.7%) and relative hypokinesis of the midventricular (-14.1 ± 6.0%) and apical (-8.9 ± 5.1%) segments. With exercise, global RVLSS increased significantly (p = 0.0005), however despite normal basal contractility at rest, there was no further augmentation with exercise. Mid and apical RVLSS increased with exercise suggestive of RV contractile reserve. In patients with resting RVSP < 35 mmHg, global and segmental RVLSS increased with exercise. In patients with resting RVSP ≥ 35 mmHg, global and segmental RVLSS did not increase with exercise and there was evidence of exertional RV dilation. Exercise provocation in conjunction with RVLSS identified differential regional contractile response to exercise in SSc patients. We further demonstrate the effect of increased loading conditions on RV contractile response exercise. These findings suggest subclinical impairments in RV reserve in SSc that may be missed by resting noninvasive 2DE-based assessments alone.

Defining the Role of Point-of-Care Ultrasound in Cardiovascular Disease.

Echocardiography is the foundation for diagnostic cardiac testing, allowing for direct identification and management of various conditions. Point-of-care ultrasound (POCUS) has emerged as an invaluable tool for bedside diagnosis and management. The objective of this review is to address the current use and clinical applicability of POCUS to identify, triage, and manage a wide spectrum of cardiac conditions. POCUS can change diagnosis and management decisions of various cardiovascular conditions in a range of settings. In the outpatient setting, it is used to risk stratify and diagnose a variety of medical conditions. In the emergency department (ED) and critical care settings, it is used to guide triage and critical care interventions. Furthermore, the skills needed to perform POCUS can be taught to noncardiologists in a way that is retained and allows identification of normal and grossly abnormal cardiac findings. Various curricula have been developed that teach residents and advanced learners how to appropriately employ point-of-care ultrasound. In conclusion, POCUS can be a useful adjunct to the physical exam, particularly in critical care applications.

Acute Cardiac Effects of Severe Pre-Eclampsia.

BACKGROUND: Pre-eclampsia with severe features (PEC) is a pregnancy-specific syndrome characterized by severe hypertension and end-organ dysfunction, and is associated with short-term adverse cardiovascular events, including heart failure, pulmonary edema, and stroke. OBJECTIVES: The authors aimed to characterize the short-term echocardiographic, clinical, and laboratory changes in women with PEC, focusing on right ventricular (RV) systolic pressure (RVSP) and echocardiographic-derived diastolic, systolic, and speckle tracking parameters. METHODS: In this prospective observational study, the authors recruited 63 women with PEC and 36 pregnant control patients. RESULTS: The PEC cohort had higher RVSP (31.0 ± 7.9 mm Hg vs. 22.5 ± 6.1 mm Hg; p < 0.001) and decreased global RV longitudinal systolic strain (RVLSS) (-19.6 ± 3.2% vs. -23.8 ± 2.9% [p < 0.0001]) when compared with the control cohort. For left-sided cardiac parameters, there were differences (p < 0.001) in mitral septal e' velocity (9.6 ± 2.4 cm/s vs. 11.6 ± 1.9 cm/s), septal E/e' ratio (10.8 ± 2.8 vs. 7.4 ± 1.6), left atrial area size (20.1 ± 3.8 cm2 vs. 17.3 ± 2.9 cm2), and posterior and septal wall thickness (median [interquartile range]: 1.0 cm [0.9 to 1.1 cm] vs. 0.8 cm [0.7 to 0.9 cm], and 1.0 cm [0.8 to 1.2 cm] vs. 0.8 cm [0.7 to 0.9 cm]). Eight women (12.7%) with PEC had grade II diastolic dysfunction, and 6 women (9.5%) had peripartum pulmonary edema. CONCLUSIONS: Women with PEC have higher RVSP, higher rates of abnormal diastolic function, decreased global RVLSS, increased left-sided chamber remodeling, and higher rates of peripartum pulmonary edema, when compared with healthy pregnant women.

The E-wave propagation index (EPI): A novel echocardiographic parameter for prediction of left ventricular thrombus. Derivation from computational fluid dynamic modeling and validation on human subjects.

BACKGROUND: To describe the derivation and validation of a novel echocardiographic metric for prediction of left ventricle thrombus (LVT). METHODS: Computational fluid dynamic modeling using cardiac CT images was used to derive a novel echocardiography-based metric to predict the presence of LVT. We retrospectively reviewed 25 transthoracic echocardiograms showing definite LVT (LVT group). We then randomly selected 25 patients with LVEF ≥55% (Normal EF group) and 25 patients with severe cardiomyopathy (CMP) with LVEF ≤40% without evidence of LVT (CMP group). The E-wave Propagation Index (EPI) was measured as the E-wave velocity time-integral divided by the LV length. An EPI>1 indicates penetration of the mitral jet into the apex whereas an EPI<1 is indicative of incomplete apical washout. The mean EPI was compared between the three groups. Crude and adjusted odd ratios of EPI and LVT association were also measured. RESULTS: Mean EPI was highest for the normal EF group and lowest in the LVT group (1.7 vs. 0.8; p<0.0001). Mean EPI also differed significantly between LVT and CMP groups (0.8 vs. 1.2; p<0.0001). 88% of the LVT group had EPI <1.0 compared to only 20% of the CMP group (p<0.0001). Among the LVT and CMP groups, an EPI <1 increased the odd ratio of LVT by 53.7 times (95% CI: 6.9-416) controlling for LVEF and LV volume. CONCLUSIONS: The E-wave propagation index is a novel, easily-obtainable, echocardiographic metric to evaluate apical LV flow. An EPI of less than 1 is an independent predictor of LVT formation.

Transoesophageal echocardiography predictors of periprocedural cerebrovascular accident in patients undergoing catheter ablation of atrial fibrillation.

AIMS: To assess the utility of transoesophageal echocardiography (TEE) parameters such as spontaneous echo contrast (SEC), left atrial (LA) appendage velocities, and aortic plaque in predicting periprocedural cerebrovascular accidents (CVAs) in patients undergoing catheter ablation of atrial fibrillation (AF). METHODS AND RESULTS: Five hundred and seventy-nine consecutive patients underwent catheter ablation of AF with pre-procedural TEE, 94% of whom also received pre-procedural warfarin and enoxaparin bridging. Of the 579 patients, 10 patients (cases) who developed periprocedural CVA (1.7%) and 40 randomly selected patients who did not develop CVA (controls) were included (50 study patients, age 58 ± 11 years, 82% male, 54% persistent AF). Periprocedural CVA was defined as a new neurological deficit that occurred anytime between the start of the procedure and 30 days after AF ablation. Demographic, clinical, and TEE variables of cases and controls were compared using standard statistical analyses. Patients with CVA more often had coronary artery disease [odds ratio (OR) 6.0, P = 0.03], previous history of CVA (OR 8.2, P = 0.02), and CHADS(2) score ≥ 2 (OR 5.4, P = 0.03) than patients without CVA. There was no difference in any of the TEE parameters (SEC, LA appendage velocity and area, patent foramen ovale, atrial septal aneurysm, valve abnormality, and aortic plaque). When these TEE parameters were adjusted for coronary artery disease, prior CVA and CHADS(2) ≥ 2, none emerged as an independent predictor of CVA. CONCLUSION: Transoesophageal echocardiographic variables (other than LA thrombus) were not associated with the occurrence of periprocedural CVA in our patients undergoing catheter ablation of AF who generally received pre-procedural anticoagulation. Despite serving as markers of a thrombogenic milieu, the presence of SEC, low LA appendage velocities, and aortic plaque may not increase the risk of periprocedural CVA after AF ablation.

Diagnostic accuracy of arterial phase 64-slice multidetector CT angiography for left atrial appendage thrombus in patients undergoing atrial fibrillation ablation.

INTRODUCTION: Multidetector CT (MDCT) is used prior to atrial fibrillation ablation (AFA) to anatomically guide ablation procedures. Whether 64-slice MDCT also can be used to diagnose left atrial thrombus is not known. METHODS: We sought to determine the accuracy and interobserver variability of MDCT in the evaluation of left atrial thrombus prior to AFA. We enrolled 50 patients scheduled for AFA who underwent 64-slice MDCT scan and transesophageal echocardiography prior to the procedure. Three experienced observers reviewed all the MDCT images for the presence of a left atrial thrombus, and two different readers interpreted the transesophageal echocardiograms (TEE), which were used as the gold standard. All observers were blinded to clinical data and each other. RESULTS: Interobserver variability between the three MDCT readers was poor (highest kappa statistic 0.43, P = 0.001). Diagnostic accuracy was highly variable, with sensitivities ranging from 100% to 50% and specificities ranging from 85% to 44%. TEE reader agreement was 98%. CONCLUSION: MDCT demonstrates high interobserver variability and has only modest diagnostic accuracy for the detection of left atrial thrombus in patients undergoing AFA procedure. Potential factors affecting the accuracy of MDCT include image quality and the difficulty of distinguishing clot from pectinate muscle. MDCT likely is not the optimal method to detect left atrial thrombus using current techniques and standards of interpretation.

Echocardiographic findings in classical and hypermobile Ehlers-Danlos syndromes.

Structural cardiovascular alterations in the classical and hypermobile forms of Ehlers-Danlos syndrome(EDS) warrant investigation. We have examined a cohort of 38 patients with hypermobile and classical EDSs using two-dimensional echocardiography. The cohort includes 7 males and 31 females, with an age range from 12-60 years. Altered echocardiographic parameters were seen in the initial cross-sectional data analysis in 24/38 patients. Five of the 38 participants had mildly dilated aortic root (AR) or sinuses of Valsalva (SV), and an additional 7 patients had an abnormal pouching of the SV, although the absolute dimensions did not exceed the normal range. Ten patients had mild mitral, tricuspid, or aortic regurgitation, and only one patient had mitral valve prolapse (MVP). Three patients had low normal systolic function; three had evidence of mildly elevated pulmonary pressures, and two patients had mild concentric left ventricular hypertrophy (LVH). Five patients had evidence of impaired left ventricular relaxation (LVR) based on mitral valve E to A velocity ratio. Interestingly, 26/38 subjects demonstrated a prominent right coronary artery (RCA) easily visualized by trans-thoracic echocardiography, and 10/38 had an elongated cardiac silhouette on the 4-chamber apical views. The "pouching" shape of the SV was more common in hypermobile type than in the classical type of EDS. The study is ongoing and will accrue longitudinal data on 100 subjects with classical and hypermobile EDSs at 2-year intervals.

Comparison of B-type natriuretic peptide levels in patients with heart failure with versus without mitral regurgitation.

Functional mitral regurgitation (MR) occurs most often in patients with heart failure (HF) and is associated with an adverse prognosis. Recently, B-type natriuretic peptide (BNP) has been validated as a marker of cardiac function and prognosis. We sought to assess the relation between functional MR and BNP levels in patients with HF, and hypothesized that MR is associated with higher BNP levels. In all, 201 patients admitted with the diagnosis of HF had a transthoracic echocardiogram and measurement of BNP levels within 48 hours. MR was graded as none/trace, mild, moderate, or severe using recently published guidelines of the American Society of Echocardiography. BNP was measured by a commercially available instrument (Biosite). The relation of MR to BNP was assessed using multivariable linear regression methods with a Tobin estimation to account for the truncation of BNP values at an upper limit of 1,300 pg/ml. Mean age of the patients was 67 +/- 11 years. The median BNP level was 826 pg/ml. The etiology of HF was predominantly diastolic in 64 patients (32%); 137 patients (68%) had significant left ventricular (LV) systolic dysfunction. Mean LV ejection fraction was 37 +/- 17%. MR was present in 112 patients (56%). After adjusting for clinical, hemodynamic, and echocardiographic variables, only LV ejection fraction (p = 0.016) and moderate or severe MR (p = 0.023) were significantly associated with BNP. When MR was grouped as any MR versus no MR, only LV ejection fraction (p = 0.017) and any degree of MR (p = 0.029) were significantly associated with BNP.

Myocardial contractile reserve by dobutamine stress echocardiography predicts improvement in ejection fraction with beta-blockade in patients with heart failure: the Beta-Blocker Evaluation of Survival Trial (BEST).

BACKGROUND: beta-Blockers improve survival and reduce hospitalization in chronic heart failure (CHF) by biologically improving left ventricular ejection fraction (LVEF). However, a good predictor of improvement with this therapy has not been identified. This substudy of BEST examined whether myocardial contractile reserve, as determined by dobutamine stress echocardiography, predicts improvement in LVEF. METHODS AND RESULTS: Seventy-nine patients with class III/IV CHF underwent dobutamine stress echocardiography before treatment with bucindolol (n=41) or placebo (n=38). Regional wall motion score index (WMSI) was calculated as the sum of the scores in each segment divided by the total number of segments visualized. WMSI was compared with change in LVEF after 3 months of therapy as determined by gated radionuclide scan. Change in WMSI correlated inversely with change in LVEF after 3 months of bucindolol (r=-0.72, P<0.0001) and was the most significant multivariate predictor of change in LVEF (P=0.0002). Patients with contractile reserve had demographics similar to those of patients without contractile reserve, including RVEF, LVEF, systolic blood pressure, and CHF duration. However, patients without contractile reserve had higher baseline plasma norepinephrine levels (687+/-333 versus 420+/-246 pg/mL, P<0.05) and greater decrease in plasma norepinephrine in response to bucindolol (-249+/-171 versus -35+/-277 pg/mL, P<0.05). CONCLUSIONS: This study suggests a direct relationship between contractile reserve and improvement in LVEF with beta-blocker therapy in patients with advanced CHF. Patients without contractile reserve have higher resting adrenergic drive, as reflected by plasma norepinephrine, and may experience greater sympatholytic effects from bucindolol.

Bioeffects of myocardial contrast microbubble destruction by echocardiography.

BACKGROUND: Microbubble destruction during contrast echocardiography is known to cause capillary leaks and red blood cell extravasation in skeletal muscle. This study evaluated the biological effects of microbubble destruction on cardiac muscle. METHODS: Contrast echocardiography was performed in 36 rats randomized to receive either Definity or Optison at a mechanical index (MI) of 1.6, 1.2, or 0.8. Myocardial bioeffects were assessed by measuring left ventricular (LV) size and fractional area shortening and histopathology. In addition, blood samples for troponin T were drawn at baseline, postinfusion (30 minutes), day 1, day 4, and day 7. LV size and function were measured at baseline and immediately prior to euthanasia on day 7, after which the heart was removed and sectioned for histopathology. RESULTS: There was no statistical difference in LV size or function regardless of the contrast agent or MI, nor was there any histopathological evidence of myocardial damage. However, troponin T increased over time (F = 3.77, P = 0.012), peaking at 30 minutes and returning to normal by day 4. The difference between Definity and Optison was not statistically significant. However, troponin T values were higher at a higher MI (F = 5.01, P = 0.012). Of 12 rats imaged at a MI of 1.6, 9 (75%) had elevated troponin T as compared to 4 (33%) of 12 at a MI of 1.2. None of the 12 rats imaged at a MI of 0.8 had an elevated troponin T at any time point. CONCLUSIONS: Microbubble destruction at high acoustic power (MI 1.6) can cause mild troponin T elevations that are not associated with LV dysfunction or histopathological evidence of myocardial damage.