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Radiation therapy is an important component of cancer therapy for many malignancies. With improvements in cardiac-sparing techniques, radiation-induced cardiac dysfunction has decreased but remains a continued concern. In this review, we provide an overview of the evolution of radiotherapy techniques in thoracic cancers and associated reductions in cardiac risk. We also highlight data demonstrating that in some cases radiation doses to specific cardiac substructures correlate with cardiac toxicities and/or survival beyond mean heart dose alone. Advanced cardiac imaging, cardiovascular risk assessment, and potentially even biomarkers can help guide post-radiotherapy patient care. In addition, treatment of ventricular arrhythmias with the use of ablative radiotherapy may inform knowledge of radiation-induced cardiac dysfunction. Future efforts should explore further personalization of radiotherapy to minimize cardiac dysfunction by coupling knowledge derived from enhanced dosimetry to cardiac substructures, post-radiation regional dysfunction seen on advanced cardiac imaging, and more complete cardiac toxicity data., Central Illustration, Highlights • Despite improvements in radiation techniques, radiation-induced cardiac dysfunction can occur in those with thoracic cancers. • Newer studies have examined associations between cardiac substructure doses and cardiac outcomes and/or survival. • Advanced cardiac imaging allows assessment of regional dysfunction after cardiac radiation exposure. • Enhanced dose tracking, imaging, and comprehensive clinical data hold promise for personalized approaches to minimize cardiotoxicity.

Highlights • Acute cardiac injury (elevated Troponin) ranges from 8 to 28% in COVID-19 patients. • Standard overt cardiac dysfunction in TTE among COVID-19 patients is uncommon. • However, signs of subclinical myocardial dysfunction by GLS is prevalent., Background The incidence of acute cardiac injury in COVID-19 patients is very often subclinical and can be detected by cardiac magnetic resonance imaging. The aim of this study was to assess if subclinical myocardial dysfunction could be identified using left ventricular global longitudinal strain (LV-GLS) in patients hospitalized with COVID-19. Methods We performed a search of COVID-19 patients admitted to our institution from January 1st, 2020 to June 8th, 2020, which revealed 589 patients (mean age = 66 ± 18, male = 56%). All available 60 transthoracic echocardiograms (TTE) were reviewed and off-line assessment of LV-GLS was performed in 40 studies that had sufficient quality images and the views required to calculate LV-GLS. We also analyzed electrocardiograms and laboratory findings including inflammatory markers, Troponin-I, and B-type natriuretic peptide (BNP). Results Of 589 patients admitted with COVID-19 during our study period, 60 (10.1%) underwent TTE during hospitalization. Findings consistent with overt myocardial involvement included reduced ejection fraction (23%), wall motion abnormalities (22%), low stroke volume (82%) and increased LV wall thickness (45%). LV-GLS analysis was available for 40 patients and was abnormal in 32 patients (80%). All patients with LV dysfunction had elevated cardiac enzymes and positive inflammatory biomarkers. Conclusions Subclinical myocardial dysfunction as measured via reduced LV-GLS is frequent, occurring in 80% of patients hospitalized with COVID-19, while prevalent LV function parameters such as reduced EF and wall motion abnormalities were less frequent findings. The mechanism of cardiac injury in COVID-19 infection is the subject of ongoing research.

Background The right ventricle is a complex structure that is challenging to quantify by two-dimensional (2D) echocardiography. Unlike disk summation three-dimensional (3D) echocardiography (3DE), single-beat 3DE can acquire large volumes at high volume rates in one cardiac cycle, avoiding stitching artifacts or long breath-holds. The aim of this study was to assess the accuracy and test-retest reproducibility of single-beat 3DE for quantifying right ventricular (RV) volumes in adult populations of acquired RV pressure or volume overload, namely, pulmonary hypertension (PH) and carcinoid heart disease, respectively. Three-dimensional and 2D echocardiographic indices were also compared for identifying RV dysfunction in PH. Methods A prospective cross-sectional study was performed in 100 individuals who underwent 2D echocardiography, 3DE, and cardiac magnetic resonance imaging: 49 patients with PH, 20 with carcinoid heart disease, 11 with metastatic carcinoid tumors without cardiac involvement, and 20 healthy volunteers. Two operators performed test-retest acquisition and postprocessing for inter- and intraobserver reproducibility in 20 subjects. Results: RV single-beat 3DE was attainable in 96% of cases, with mean volume rates of 32 to 45 volumes/sec. Bland-Altman analysis of all subjects (presented as mean bias ± 95% limits of agreement) revealed good agreement for end-diastolic volume (−2.3 ± 27.4 mL) and end-systolic volume (5.2 ± 19.0 mL) measured by 3DE and cardiac magnetic resonance imaging, with a tendency to underestimate stroke volume (−7.5 ± 23.6 mL) and ejection fraction (−4.6 ± 13.8%) by 3DE. Subgroup analysis demonstrated a greater bias for volumetric underestimation, particularly in healthy volunteers (end-diastolic volume, −11.9 ± 18.0 mL; stroke volume, −11.2 ± 20.2 mL). Receiver operating characteristic curve analysis showed that 3DE-derived ejection fraction was significantly superior to 2D echocardiographic parameters for identifying RV dysfunction in PH (sensitivity, 94%; specificity, 88%; area under the curve, 0.95; P = .031). There was significant interobserver test-retest bias for RV volume underestimation (end-diastolic volume, −12.5 ± 28.1 mL; stroke volume, −10.6 ± 23.2 mL). Conclusions Single-beat 3DE is feasible and clinically applicable for volumetric quantification in acquired RV pressure or volume overload. It has improved limits of agreement compared with previous disk summation 3D echocardiographic studies and has incremental value over standard 2D echocardiographic measures for identifying RV dysfunction. Despite the ability to obtain and postprocess a full-volume 3D echocardiographic RV data set, the quality of the raw data did influence the accuracy of the data obtained. The technique performs better with dilated rather than nondilated RV cavities, with a learning curve that might affect the test-retest reproducibility for serial RV studies.