The association between thyroid hormones and cardiovascular conditions has been well studied, specifically, the effects of hypothyroidism on cardiomyopathy, and hyperthyroidism with arrhythmias. Nonetheless, an explicit correlation between hyperthyroidism and cardiomyopathy has yet to be established. Medical databases MEDLINE and PubMed were accessed and queried as primary sources for data acquisition. Search criteria consisted of "hyperthyroidism", "heart failure", and "thyroid and cardiovascular system", which allowed the retrieval of relevant and recent works. From these sources, a consensus was developed and employed to yield an updated review of the etiology of heart failure in the setting of hyperthyroidism. It is rare for patients with hyperthyroidism to remain in a chronic hyperthyroid state, making it difficult to analyze subsequent long-term effects on the cardiovascular system. Related to heart failure, some studies have demonstrated no change in ejection fraction, while others have shown an acute change along with diastolic dysfunction, with or without an underlying rhythm abnormality. Further investigation is warranted to elucidate the mechanism driving such cardiac dysfunction, and whether it is due to vascular changes, tachyarrhythmias, or myocyte remodeling and fibrosis. The intent of this review article is to improve our understanding of how a hyperthyroid state affects cardiovascular function. An enhanced understanding of the effects on cardiovascular physiology will afford physicians the ability to provide more comprehensive care in consideration of both endocrine and cardiovascular pathologies.

BackgroundPrior diagnosis of heart failure (HF) is associated with increased length of hospital stay (LOS) and mortality from COVID-19. Associations between substance use, venous thromboembolism (VTE) or peripheral arterial disease (PAD) and its effects on LOS or mortality in patients with HF hospitalised with COVID-19 remain unknown.ObjectiveThis study identified risk factors associated with poor in-hospital outcomes among patients with HF hospitalised with COVID-19.MethodsCase–control study was conducted of patients with prior diagnosis of HF hospitalised with COVID-19 at an academic tertiary care centre from 1 January 2020 to 28 February 2021. Patients with HF hospitalised with COVID-19 with risk factors were compared with those without risk factors for clinical characteristics, LOS and mortality. Multivariate regression was conducted to identify multiple predictors of increased LOS and in-hospital mortality in patients with HF hospitalised with COVID-19.ResultsTotal of 211 patients with HF were hospitalised with COVID-19. Women had longer LOS than men (9 days vs 7 days; p<0.001). Compared with patients without PAD or ischaemic stroke, patients with PAD or ischaemic stroke had longer LOS (7 days vs 9 days; p=0.012 and 7 days vs 11 days, p<0.001, respectively). Older patients (aged 65 and above) had increased in-hospital mortality compared with younger patients (adjusted OR: 1.04; 95% CI 1.00 to 1.07; p=0.036). Prior diagnosis of VTE increased mortality more than threefold in patients with HF hospitalised with COVID-19 (adjusted OR: 3.33; 95% CI 1.29 to 8.43; p=0.011).ConclusionVascular diseases increase LOS and mortality in patients with HF hospitalised with COVID-19.

Background  Acute myocardial infarction in pregnancy is occasionally due to spontaneous coronary artery dissection (SCAD). Although uncommon, the majority of cases of pregnancy-associated SCAD (pSCAD) has critical presentations with more profound defects that portend high maternal and foetal mortality, and frequently necessitate preterm delivery. This is a case of pSCAD with ongoing ischaemia that required temporary mechanical circulatory support (MCS) and emergent revascularization, while the pregnancy was successfully continued to early-term. Case summary  A 30-year-old woman G2P1 at Week 32 of gestation with no medical history, presented to the emergency department with severe chest pain. An electrocardiogram showed ST-segment elevation in the anterolateral leads. An emergent cardiac catheterization revealed dissection of the proximal left anterior descending (LAD) artery with TIMI (thrombolysis in myocardial infarction) 3 flow. Although initially stable, she later experienced recurrent chest pain and developed cardiogenic shock, necessitating MCS, and emergent revascularization. She was stabilized and remained closely monitored in the hospital prior to vaginal delivery at early-term. Discussion  This case of pSCAD at Week 32 of gestation complicated by refractory ischaemia illustrates the complexity of management, which requires a multi-disciplinary team to reduce both maternal and foetal mortality. Conservative management of SCAD, while preferred, is not always possible in the setting of ongoing ischaemia, particularly if complicated by cardiogenic shock. A thorough weighing of risks vs. benefits and ongoing discussions among multiple subspecialists in this case allowed for the stabilization of the patient and subsequent successful early-term delivery.

Background: Heart failure with reduced ejection fraction (HFrEF) is associated with recurrent hospitalizations and high mortality. Guideline-directed medical therapy (GDMT) reduces morbidity, mortality and re-admission rates. Despite the evidence, less than 50% of patients with HFrEF are prescribed appropriate medical therapy. When hospitalized patients have these medications discontinued on admission or during hospitalization, they are less likely to have them restarted on discharge. The goal of this study was to determine the incidence of disruption of beta-blocker (BB) therapy during hospitalization for HFrEF patients admitted to an academic tertiary referral hospital. Methods:We conducted a retrospective study in a single teaching hospital over the course of 1 year, and utilized data queried from the electronic medical record (EPIC) database. Inclusion criteria were met by patients with an ICD-10 code diagnosis of heart failure, left ventricular ejection fraction less than 40% and BB prescription prior to admission. Additional information noted included age, sex, vital signs throughout the admission and dates where BB was not given for a full 24-h period. Patients in the intensive care unit (ICU) were excluded due to uncertainty of their hemodynamics. Data were extracted from the electronic medical record database and analyzed through Python, Microsoft Excel and RStudio. The incidence of BB disruption during hospitalization was defined as a 24-h period where no BB was administered. Blood pressure (BP) and heart rate (HR) levels were compared between patients who received BB and patients who had a disruption in their BB. Measurements were also obtained to assess whether a correlation exists between holding BB therapy and time of the year, age, or sex.Results: Between January 2018 and January 2019, 780 patient encounters met inclusion criteria for the study. Patients who were continued on BB therapy had an average BP of 120.8/68.7 mm Hg and an HR of 82.4 bpm on days they received their BB. Patients who had a disruption of BB therapy had an average BP of 117.7/67.6 mm Hg and an HR of 88.6 bpm on the days of the disruption (P < 0.001). There was no association between holding BB and age, sex, or time of year.Conclusions: This study showed that in an academic tertiary referral center, patients with HFrEF who are not in an ICU have a 23% chance of not receiving their recommended BB therapy for 24 h. While the differences measured for BP and HR are statistically significant, they are not clinically significant.