Characterization of Primary Mitral Regurgitation With Flail Leaflet and/or Wall-Impinging Flow.

BACKGROUND: Echocardiography guidelines note that a flail leaflet is a specific criterion for severe mitral regurgitation (MR) and that regurgitant severity is underestimated in wall-impinging jets (Coanda effect). Both findings are often considered to be pathognomonic of severe MR. OBJECTIVES: In this study, the authors sought to determine the association of flail leaflet and Coanda effect with MR severity quantified by means of cardiac magnetic resonance (CMR). METHODS: The authors enrolled 158 consecutive patients with primary MR according to echocardiography and CMR. The presence of a flail leaflet or Coanda was determined for each patient. CMR regurgitant volume (RV) and regurgitant fraction (RF) were quantified for all patients. RESULTS: There were 55 patients (35%) with a flail leaflet, 52 (33%) with Coanda, and 22 (14%) with a flail leaflet and Coanda. The mean CMR mitral RV and RF progressively increased in patients without a Coanda or flail, a Coanda, a flail, or a Coanda and a flail (RV: 28 ± 21 mL vs 43 ± 23 mL vs 58 ± 29 mL vs 64 ± 25 mL [P < 0.001]; RF: 25% ± 16% vs 34% ± 14% vs 41% ± 12% vs 45% ± 12% [P < 0.001]). With the use of CMR RV, 35%, 46%, and 59% of patients had severe MR with the presence of a Coanda, flail leaflet, or both, respectively. With the use of CMR RF, 25%, 31%, and 40% of patients had severe MR with the presence of a Coanda, flail leaflet, or both, respectively. CONCLUSIONS: While the presence of a flail leaflet and Coanda effect on echocardiography are associated with higher regurgitant volumes and fractions, they are frequently not associated with severe MR as assessed by means of CMR. (Comparison Study of Echocardiography and Cardiovascular Magnetic Resonance Imaging in the Assessment of Mitral and Aortic Regurgitation; NCT04038879).

Use of a Smartwatch for Assessment of the QT Interval in Outpatients with Coronavirus Disease 2019.

The coronavirus disease 2019 (COVID-19) pandemic has necessitated rapid implementation of innovative strategies to manage patients remotely to help reduce the risk of community and nosocomial transmission. This case demonstrates the use of an Apple Watch (Apple, Cupertino, CA, USA) to monitor for arrhythmias and QT prolongation in a patient with COVID-19 during home isolation.

Coronary risk equivalence of diabetes assessed by SPECT-MPI.

BACKGROUND: Several publications and guidelines designate diabetes mellitus (DM) as a coronary artery disease (CAD) risk equivalent. The aim of this investigation was to examine DM cardiac risk equivalence from the perspective of stress SPECT myocardial perfusion imaging (MPI). METHODS AND RESULTS: We examined cardiovascular outcomes (cardiac death or nonfatal MI) of 17,499 patients referred for stress SPECT-MPI. Patients were stratified into four categories: non-DM without CAD, non-DM with CAD, DM without CAD, and DM with CAD, and normal or abnormal perfusion. Cardiac events occurred in 872 (5%), with event-free survival best among non-DM without CAD, worst in DM with CAD, and intermediate in DM without CAD, and non-DM with CAD. After multivariate adjustment, risk remained comparable between DM without CAD and non-DM with CAD [AHR 1.0 (95% CI 0.84-1.28), P =0.74]. Annualized event rates for normal subjects were 1.4% and 1.6% for non-DM with CAD and DM without CAD, respectively (P = 0.48) and 3.5% (P = 0.95) for both abnormal groups. After multivariate adjustment, outcomes were comparable within normal [AHR 1.4 (95% CI 0.98-1.96) P = 0.06] and abnormal [AHR 1.1 (95% CI 0.83-1.50) P = 0.49] MPI. CONCLUSIONS: Diabetic patients without CAD have comparable risk of cardiovascular events as non-diabetic patients with CAD after stratification by MPI results. These findings support diabetes as a CAD equivalent and suggest that MPI provides additional prognostic information in such patients.

Broken lung and broken heart: a case of right pneumothorax resulting in Takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TC), also known as broken-heart syndrome, is usually the result of a stressful event. It is more common in postmenopausal females and can mimic an acute coronary syndrome. We report the case of an elderly female who presented with acute chest pain and ECG changes suggestive of an acute myocardial infarction, but later was found to have right-sided pneumothorax with TC. The case highlights the growing interest in stress cardiomyopathy and its variable modes of presentation. It also reminds us that the acute chest pain of a pneumothorax can closely mimic a coronary event with similar electrocardiographic changes.

A strategy of symptom-limited exercise with regadenoson-as-needed for stress myocardial perfusion imaging: a randomized controlled trial.

BACKGROUND: Ambulatory patients with uncertain functional capacity may benefit from combined exercise and vasodilator stress protocols for myocardial perfusion imaging (MPI). The safety and MPI image quality with regadenoson administered during symptom-limited exercise have not been prospectively evaluated. METHODS AND RESULTS: A total of 140 patients (mean age 61 years, 48% female) referred for exercise with vasodilator stress MPI were randomized 2:1 to a strategy of exercise with regadenoson-as-necessary (Ex-Reg, n = 96) or dipyridamole with exercise (Dip-Ex, n = 44) after Duke Activity Status Index (DASI) scoring (median score 28 vs 24, P = .09). Ex-Reg subjects commenced treadmill exercise and regadenoson was administered only if the subject was unable to reach standard endpoints. Dip-Ex subjects received dipyridamole prior to symptom-limited exercise. Hemodynamics were recorded throughout. Subjects completed symptom questionnaires and MPI image quality was assessed by blinded read. Ex-Reg subjects were more likely to achieve ≥85% age-predicted maximum heart rate than Dip-Ex subjects (57% vs 32%, P < .01). Only 50% of subjects meeting inclusion criteria and randomized to Ex-Reg required regadenoson and none had symptomatic hemodynamic changes. Severe side effects or adverse events occurred in 16% of Ex-Reg and 24% of Dip-Ex subjects (P = .12). MPI image quality was "good" or "excellent" in 88% of Ex-Reg subjects and 86% of Dip-Ex subjects (P = .33). CONCLUSION: A strategy of exercise with regadenoson-as-needed for MPI offers similar safety and side effect profile with similar image quality compared to dipyridamole with exercise, with reduced pharmaceutical use.

Reduced expression of the LIM-homeobox gene Lhx3 impairs growth and differentiation of Rathke's pouch and increases cell apoptosis during mouse pituitary development.

The formation of the anterior and intermediate lobes of the pituitary gland is a multi-step process regulated by cell-cell interactions involving a number of signaling pathways and by cascades of cell-intrinsic transcription factors. The LIM-homeodoamin protein Lhx3 has previously been shown to play an essential role in the growth of Rathke's pouch, a primordium of the anterior and intermediate lobes of the pituitary. However, the mechanisms underlying the function and regulation of Lhx3 remain to be elucidated. Here we report that a targeted insertion of a DNA fragment in the 3'-untranslated region of the Lhx3 gene reduces the expression of both Lhx3 mRNA and protein in Rathke's pouch. Mutant mice homozygous for this Lhx3 allele show severe hypoplasia of the pouch, a defect identical to that observed in Lhx3-null mutants. To gain insights into the mechanism of Lhx3 function in pituitary development, we further analyzed the Lhx3 deficient mutants by examination of early pituitary marker expression, cell proliferation, and cell apoptosis. Our results revealed an increase in cell apoptosis and a loss of Islet1 and Calbindin marker expression in Rathke's pouch of these mutants. Recently, increased cell apoptosis in Rathke's pouch has been described in mutant mice impaired in the function of the bicoid-like homeodomain proteins Pitx1 and Pitx2. In those mutants, the expression of Lhx3 is absent. Our results thus underscore the view that Lhx3 functions downstream of the Pitx factors in the same transcriptional cascade that controls growth and early cell differentiation of the developing pituitary gland.