Chaliki, Hari P.

Abstract Primary cardiac sarcoma is a rare type of intracardiac mass. This report describes a patient with atrial flutter who had a new right atrial mass incidentally discovered on transesophageal echocardiography. A thrombus was suspected based on radiographic appearance, but there was minimal change with anticoagulation. The mass was resected and found to be an undifferentiated pleomorphic cardiac sarcoma, an uncommon sub-type within the already rare category of primary cardiac neoplasms. This report highlights the importance of considering primary malignancy and thoroughly correlating radiographic and clinical evidence during the diagnostic workup of patients with intracardiac masses.

Background: Cellular transplantation has emerged as promising approach for treating cardiac diseases. However, a poor engraftment rate limits our understanding on how transplanted cardiomyocytes contribute to cardiac function in the recipient’s heart. Methods: The CRISPR/Cas9 technique was employed for stable and constitutive gene expression in human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs). Myocardial infarction was induced in adult immunodeficient mice, followed by intramyocardial injection of hiPSC-CMs expressing either CCND2/channelrhodopsin 2 (hiPSC-CCND2OE/ChR2OECMs) or CCND2/luciferase (hiPSC-CCND2OE/LuciOECMs). Six months later, hemodynamics and intramural electrocardiogram were recorded upon blue light illuminations in anesthetized, open-chest mice. Results: Blue light resets automaticity of spontaneously beating hiPSC-CCND2OE/ChR2OECMs in culture, but not that of hiPSC-CCND2OE/LuciOECMs. Response to blue light was also observed in mice carrying large (>106 cells) intracardiac grafts of hiPSC-CCND2OE/ChR2OECM but not in mice carrying hiPSC-CCND2OE/LuciOECMs. The former exhibited single premature ventricular contractions upon light illumination or ventricular quadrigeminy upon second-long illuminations. At the onset of premature ventricular contractions, maximal systolic ventricular pressure decreased while ventricular volume rose concomitantly. Light-induced changes reversed upon resumption of sinus rhythm. Conclusions: We established an in vivo model for optogenetic-based modulation of the excitability of donor cardiomyocytes in a functional, reversible, and localized manner. This approach holds unique value for studying electromechanical coupling and molecular interactions between donor cardiomyocytes and recipient hearts in live animals.

Background: Patient-prosthesis mismatch (PPM) is still a frequently encountered problem after aortic valve surgery for aortic stenosis(AS). Advanced planning for prevention of PPM would be beneficial. We hypothesized that identification of severe PPM based on chosen surgical valve will predict development of severe PPM after surgery. Methods: Fifty one patients (74±13yrs) with severe aortic valve stenosis who underwent aortic valve surgery had postoperative echocardiogram (TTE) within 6 months. Severe PPM was defined as effective orifice area index (EOAI)<0.65 cm2/m2.We calculated predicted severe PPM using published references values of the prosthetic valve. We used mean value and the values one standard deviation above and below. We compared these values to the actual PPM based on postoperative TTE. Results: All patients had severe AS (MG50±7 mm Hg) and an LV EF of 56±15%. Forty four patients had tissue valves implanted and 7 had mechanical valves implanted. Mean time between postoperative TTE and surgery was 39± 60 days. When the mean reference values for the valve implanted was used, only 1 patient (2%) was predicted to have severe PPM. However, based on postoperative TTE, 6 patients (13%) had severe PPM. There was no correlation between EOAI based on postop TTE and mean published reference values (Figure).When the EOAI below one SD of the published reference value was chosen, the predicted incidence of severe PPM was 38%. When the EOAI above one SD was chosen for the reference value none of the patients were predicted to have PPM. Sensitivity and specificity to identify severe PPM was 17% and 100% for mean published reference value while it was 0% and 100% for +1 SD and 83% and 68% for -1 SD. Conclusions: 1) Use of mean published reference values markedly under estimate the true incidence of post-operative PPM and has unacceptably low sensitivity. 2) Predicted occurrence of PPM was widely variable (0% to 38%) based on the published reference values. Larger studies are needed.

Background: Pectus excavatum (PE) deformity involves posterior depression of the sternum and adjacent costal cartilages. The relationship of CT/MRI chest cardiac compression indices used as indications for surgical repair of PE with echocardiographic findings and with improvement in cardiac chamber compression and function post PE repair is unknown. Methods: We evaluated right atrial (RA) size, tricuspid annulus (TA size, right ventricular (RV) outflow tract size as well as RV 2D strain on intra-operative trans-esophageal echocardiography (TEE) immediately pre and post surgical PE repair. Inspiratory and expiratory Haller Index (HI) and cardiac compression indices (CCI) were measured on pre op CT/MR scans (Figure). Offline measurement of chamber dimensions on TEE images was performed and Speckle tracking strain measurements were made using Syngo US Workplace software (Siemens). P<0.05 was considered significant. Results: 60 patients, 73% male, 27% female, age 33.6±10.3 yrs underwent PE repair following CT/MRI from 2010-2014 (Figure). There was a strong correlation between expiratory CT/MRI chest AP diameter and pre-op RA size (panel A). Pre op RA and TA compression on TEE inversely correlated with pre op RV global longitudinal strain rate(RVGLSR) (panels B & C). CCI predicted improvement in RA size post PE repair (panels D & E). In addition pre op RA size on TEE correlated with improvement in RVGLSR post PE repair surgery (panel F). Conclusion: In patients with PE deformity, pre surgical CCI correlated with right-sided cardiac chamber compression on pre op TEE. Severity of chest and cardiac compression also predicted magnitude of improvement in right-sided chamber size and RV longitudinal deformation post PE repair. Our findings provide insight regarding the beneficial effects of PE surgery on right heart chamber compression and improvement in RV function and the important role of intraoperative TEE for patients undergoing PE repair surgery.

An 85-year-old man with cardiac history notable for atrial fibrillation diagnosed 10 years ago which was being treated with atenolol and warfarin presented to our institution with persistent atrial fibrillation. His echocardiogram showed ejection fraction (EF) of 56%, no regional wall motion abnormalities, mild mitral and pulmonary regurgitation, and trivial tricuspid regurgitation. Despite this treatment, he had recurrent episodes of paroxysmal symptomatic atrial fibrillation with a rapid rate requiring multiple emergency department visits and hospital admissions. Given difficulty to control the rate, he underwent atrioventricular (AV) nodal ablation and leadless pacemaker insertion. Fifteen days after the procedure, he was found to have a severe mitral regurgitation murmur.

ObjectivesLeft ventricular (LV) septal hypertrophy in aortic stenosis raises diagnostic and therapeutic questions. However, the etiology and clinical consequences of this finding have not been well studied. The aim of this study was to perform a morphologic evaluation of the LV in aortic stenosis and to investigate the contributing factors and consequences of septal hypertrophy.MethodsPatients with moderate or severe aortic stenosis were prospectively enrolled. Patients with previous myocardial infarction, wall motion abnormalities, at least moderate valvular regurgitation, known cardiomyopathy, an LV ejection fraction of less than 50%, and age younger than 65 years were excluded.ResultsForty‐one patients underwent a final analysis. Septal hypertrophy (LV septal wall thickness ≥15 mm) was confirmed in 21 of 41 patients. The septal hypertrophy group had higher peak aortic valve velocity, a higher diabetes mellitus rate, and a higher rate and longer duration of hypertension than those without septal hypertrophy. The peak aortic valve velocity (odds ratio, 7.1; 95% confidence interval, 1.4–37.1) and diabetes mellitus (odds ratio, 7.4; 95% confidence interval, 1.2–46.2) were the significant factors associated with septal hypertrophy by multivariate analysis. Intraventricular conduction disturbance on electrocardiography was more frequent in the septal hypertrophy group (P = .021).ConclusionsLeft ventricular septal hypertrophy was commonly observed in elderly patients with aortic stenosis, and a higher aortic valve velocity, hypertension, and diabetes mellitus were associated factors. Intraventricular conduction disturbance occurred more often in patients with septal hypertrophy than those without, which implies the pathophysiologic consequence. Further studies are needed to determine the impact of septal hypertrophy and intraventricular conduction disturbance on the prognosis of patients after aortic valve interventions.