Clinical outcomes following hospitalization for COVID-19 in patients with cardiac sarcoidosis in the United States: a propensity-matched analysis from national inpatient sample database from April 2020 to December 2021.

Background: The highly arrhythmogenic nature of cardiac sarcoidosis (CS) leads to high morbidity and mortality, the rates of which may be higher in COVID-19 patients. This study aimed to evaluate the outcomes of CS patients admitted to hospitals with COVID-19. Methods: The study utilised the 2020-2021 National Inpatient Sample database, examining primary COVID-19 cases in adults aged older than or equal to 18 years. Those with CS were identified using ICD-10 code "D86.85" and compared with and without propensity matching (1:10) to those without CS for baseline characteristics and primary outcomes of acute kidney injury (AKI), use of mechanical ventilation, cardiac arrest and mortality. Results: In total, 2 543 912 COVID-19 cases were identified. Before propensity matching, CS patients were more likely to be younger (58.0 vs. 64.0 years, P<0.01), male (64.0% vs. 52.6%, P=0.011), of Black ethnicity (60.0% vs. 15.9%, P<0.01), exhibit higher Charlson Comorbidity Index (CCI) scores (3.00 vs. 1.00, P<0.01) and had a higher incidence of in-hospital cardiac arrest (aOR 2.649, 95% CI 1.366-5.134, P=0.004). After propensity matching (CS, N=95; non-CS, N=875), those with CS were at a statistically significant reduced risk of AKI (aOR 0.484, P=0.01); however, the outcomes of death, cardiac arrest, mechanical ventilation, length of stay (LOS) and healthcare costs did not reach significance. Conclusion: In a propensity-matched cohort admitted with COVID-19, CS patients had a reduced risk of AKI, but comparable LOS, rates of cardiac arrest, mechanical ventilator use, and mortality. Future research is warranted to develop evidence-based guidelines for managing COVID-19 in patients with CS.

Pericardial tamponade in coronary interventions: Morbidity and mortality.

BACKGROUND: Cardiac tamponade or pericardial tamponade (PT) can be a complication following invasive cardiac procedures. METHODS: Patients who underwent various procedures in the cardiac catheterization lab (viz. coronary interventions) were identified using the International Classification of Diseases, Ninth and Tenth Edition, Clinical Modification (International classification of diseases [ICD]-9-Clinical modification [CM] and ICD-10-CM, respectively) from the Nationwide Inpatient Sample (NIS) database. Patient demographics, presence of comorbidities, PT-related events, and in-hospital death were also abstracted from the NIS database. RESULTS: The frequency of PT-related events in the patients undergoing CI from 2010 to 2017 ranged from 3.3% to 8.4%. Combined in-hospital mortality/morbidity of PT-related events were higher with increasing age (odds ratio [OR] [95% CI]: chronic total occlusion (CTO) = 1.19 [1.10-1.29]; acute coronary syndrome (ACS) = 1.21 [1.11-1.33], both p < 0.0001) and female sex (OR [95%CI]: CTO = 1.70 [1.45-2.00]; ACS = 1.72 [1.44-2.06], both p < 0.0001). In-hospital mortality related to PT-related events was found to be 8.5% for coronary procedures. In-hospital mortality was highest amongst the patients undergoing percutaneous transluminal coronary angioplasty (PTCA) for ACS (ACS vs. non-CTO PTCA vs. CTO PTCA: 15.7% vs. 10.4% and 14.4%, p < 0.0001 and ACS vs. non-CTO PTCA vs. CTO PTCA: 12.1% vs. 8.1% and 5.6%, p = 0.0001, respectively). CONCLUSIONS: In the real-world setting, PT-related events in CI were found to be 3.3%-8.4%, with in-hospital mortality of 8.5%. The patients undergoing PTCA for ACS were found to have highest mortality. Older patients undergoing CTO PTCA independently predicted higher mortality.

Outcomes of definite vs probable/presumed cardiac sarcoidosis: a systematic review and meta-analysis.

BACKGROUND: Diagnosing cardiac sarcoidosis (CS), which can be associated with arrhythmias and heart failure, remains challenging despite multiple advances over time. The 2014 Heart Rhythm Society (HRS) consensus statement recommends an endomyocardial biopsy (EMB) to establish a definite diagnosis of CS. In the absence of a positive EMB, a diagnosis of probable or presumed CS is made on the basis of clinical and imaging criteria. OBJECTIVE: To investigate whether there is any difference in outcomes between definite vs probable/presumed CS. METHODS: PubMed/MEDLINE, Embase, and the Cochrane Library databases were searched for relevant studies published after 2014. Risk ratios (RR) with 95% confidence intervals (CI) were calculated using the random effects model and presented in forest plots. RESULTS: 6 studies involving 2,204 patients were identified. The cohort had a mean age of 56.8 years (SD: ±13.6 years). The median duration of follow-up was 40.5 months. No statistically significant difference was observed between definite and probable/presumed CS for reduced risk of the composite endpoint (RR: 1.80, 95% CI: 0.93 to 3.49), and all-cause death (RR: 1.01, 95% CI: 0.48 to 2.10). CONCLUSION: This meta-analysis demonstrated the equivalence of clinical course and prognosis between definite and probable/presumed CS. This highlights the importance of a multi-disciplinary approach to CS care and emphasizes that histological confirmation should not be a prerequisite to diagnose or manage this condition.

Management of acute myocarditis: a systematic review of clinical practice guidelines and recommendations.

The management of acute myocarditis (AM) is addressed in multiple clinical guidelines. We systematically reviewed current guidelines developed by national and international medical organizations on the management of AM to aid clinical practice. Publications in MEDLINE, EMBASE and Cochrane were identified between 1 January 2013 and 12 April 2024. Additionally, the websites of relevant organizations and the Guidelines International Network, Guideline Central, and NHS knowledge and library hub were reviewed. Two reviewers independently screened titles and abstracts, two reviewers assessed the rigour of guideline development, and one reviewer extracted the recommendations. Two of the three guidelines identified showed good rigour of development. Those rigorously developed agreed on the definition of AM, sampling serum troponin as part of the workflow for AM, testing for B-type natriuretic peptides in heart failure, key diagnostic imaging in the form of cardiovascular magnetic resonance, coronary angiography to exclude significant coronary disease, indications for endomyocardial biopsy (EMB), and indications for immunosuppression and advanced treatment options. Discrepancies exist in sampling creatine kinase-myocardial bound as a marker of myocardial injury, indications for EMB, and indications for immunosuppression and treatment of uncomplicated AM. Evidence is lacking for the use of 18F-Fluorodeoxyglucose Positron Emission Tomography for myocardial imaging, exercise restriction, follow-up measures and genetic testing, and there are few high-quality randomized trials to support treatment recommendations. Recommendations for management of AM in the guidelines have largely been developed from expert opinion rather than trial data.

Clinical Applications of Cardiac Magnetic Resonance Parametric Mapping.

Cardiovascular magnetic resonance (CMR) imaging is widely regarded as the gold-standard technique for myocardial tissue characterization, allowing for the detection of structural abnormalities such as myocardial fatty replacement, myocardial edema, myocardial necrosis, and/or fibrosis. Historically, the identification of abnormal myocardial regions relied on variations in tissue signal intensity, often necessitating the use of exogenous contrast agents. However, over the past two decades, innovative parametric mapping techniques have emerged, enabling the direct quantitative assessment of tissue magnetic resonance (MR) properties on a voxel-by-voxel basis. These mapping techniques offer significant advantages by providing comprehensive and precise information that can be translated into color-coded maps, facilitating the identification of subtle or diffuse myocardial abnormalities. As unlikely conventional methods, these techniques do not require a substantial amount of structurally altered tissue to be visually identifiable as an area of abnormal signal intensity, eliminating the reliance on contrast agents. Moreover, these parametric mapping techniques, such as T1, T2, and T2* mapping, have transitioned from being primarily research tools to becoming valuable assets in the clinical diagnosis and risk stratification of various cardiac disorders. In this review, we aim to elucidate the underlying physical principles of CMR parametric mapping, explore its current clinical applications, address potential pitfalls, and outline future directions for research and development in this field.

Sex disparities in cardiac sarcoidosis patients undergoing implantable cardioverter-defibrillator implantation.

INTRODUCTION: In patients with cardiac sarcoidosis (CS), implantable cardioverter-defibrillators (ICDs) are important for preventing sudden cardiac death. This study aimed to investigate sex disparities in CS patients undergoing ICD implantation. METHODS: The 2016-2020 National Inpatient Sample (NIS) database compared the characteristics and outcomes of males and females with CS receiving ICDs. RESULTS: Among 760 CS patients who underwent inpatient ICD implantation, 66.4% were male. Males were younger (55.0 vs. 56.9 years, p < .01), had higher rates of diabetes (31.7% vs. 21.6%, p < .01) and chronic kidney disease (CKD) (16.8% vs. 7.8%, p < .01) but lower prevalence of atrial fibrillation (AF) (11.9% vs. 23.5%, p < .01), sick sinus syndrome (4.0% vs. 7.8%, p = .024), ventricular fibrillation (VF) (9.9% vs. 15.7%, p = .02), and black ancestry (31.9% vs. 58.0%, p < .01). Unadjusted major adverse cardiovascular events (MACE), defined as a composite of in-hospital death, myocardial infarction (MI), and ischemic stroke, was higher in females (11.8% vs. 6.9%, p = .024), but when adjusted for age and tCharlson Comorbidity Index (CCI), females demonstrated significantly lower odds of experiencing MACE (aOR: 0.048, 95% CI: 0.006-0.395, p = .005). Incidence of acute kidney injury (AKI) post-ICD was significantly lower in females (15.7% vs. 23.8%, p = .01) as was the adjusted odds (aOR: 0.282, 95% CI: 0.146-0.546, p < .01). There was comparable mean length of stay and hospital charges. CONCLUSION: ICD utilization in CS patients is more common among males, who have a higher prevalence of diabetes and CKD but a lower prevalence of AF, sick sinus syndrome, and VF. Adjusted MACE and AKI were significantly lower in females.

Characteristics and clinical outcomes of patients with sarcoidosis admitted for ST-elevation myocardial infarction in the United States: a propensity matched analysis from the National Inpatient Sample.

Introduction: Sarcoidosis is a systemic inflammatory disorder characterised by non-caseating granulomas. Cardiac sarcoidosis (CS) normally causes conduction abnormalities, ventricular arrhythmias, and heart failure. Little is known about the characteristics and impact of sarcoidosis in patients admitted with ST-elevation myocardial infarction (STEMI). This study aims to fill this void. Material and methods: Utilising the National Inpatient Sample (NIS) database (2016-2020), individuals with STEMI were identified and categorised based on sarcoidosis presence whilst adjusting for confounders via logistic regression models. Results: Among 851,290 STEMI patients, 1215 had sarcoidosis. Before propensity matching, sarcoidosis patients were notably different in demographics and comorbidities compared to non-sarcoidosis patients. After propensity score matching (PSM), sarcoidosis patients were found to have a higher incidence of supraventricular tachycardia (SVT) (2.5% vs. 1.3%, p = 0.024) and acute kidney injury (AKI) (23.3% vs. 20.8%, aOR = 1.269, 95% CI: 1.02-1.58, p = 0.033) but a lower incidence of undergoing coronary artery bypass graft (CABG) (5.5% vs. 8.5%, aOR = 0.663; 95% CI: 0.472-0.931, p = 0.018), while no significant disparities were noted in PCI, cardiogenic shock, mortality, or mean length of stay (LOS). Conclusions: Using propensity-matched large real-world data of STEMI patients, sarcoidosis was associated with fewer cases of CABG and a greater incidence of AKI and SVT compared to non-sarcoidosis patients.

Heart failure with preserved ejection fraction management: a systematic review of clinical practice guidelines and recommendations.

Multiple guidelines exist for the diagnosis and management of heart failure with preserved ejection fraction (HFpEF). We systematically reviewed current guidelines and recommendations, developed by national and international medical organizations, on the management of HFpEF in adults to aid clinical decision-making. We searched MEDLINE and EMBASE on 28 February 2024 for publications over the last 10 years as well as websites of organizations relevant to guideline development. Of the ten guidelines and recommendations retrieved, seven showed considerable rigour of development and were subsequently retained for analysis. There was consensus on the definition of HFpEF and the diagnostic role of serum natriuretic peptides and resting transthoracic echocardiography. Discrepancies were identified in the thresholds of serum natriuretic peptides and transthoracic echocardiography parameters used to diagnose HFpEF. There was agreement on the general pharmacological and supportive management of acute and chronic HFpEF. However, differences exist in strategies to identify and address specific phenotypes. Contemporary guidelines for HFpEF management agree on measures to avoid its development and the consideration of cardiac transplantation in advanced disease. There were discrepancies in recommended frequency of surveillance for patients with HFpEF and sparse recommendations on screening for HFpEF in the general population, use of diagnostic scoring systems, and the role of newly emerging therapies.

Response to letter to editor, re-predictors of morbidity and in-hospital mortality following procedure-related cardiac tamponade.

We had included only the patients with cardiac tamponade, excluded those coded for pericardial effusion. The feasibility of comparison of the databases of two regions needs to be evaluated. There are some inherent limitations for the studies carried out from the National In-patient Samples (NIS) database.

Racial disparities among patients with cardiac sarcoidosis and arrhythmias in the United States: A propensity matched-analysis from the national inpatient sample database 2016-2020.

BACKGROUND: Cardiac sarcoidosis (CS) is frequently associated with conduction abnormalities and arrhythmias. In this study, we aim to evaluate racial disparities in the frequency of arrhythmias, and associated co-morbidities, among patients with CS. METHODS: White and African American (AA) patients diagnosed with CS were identified and compared from the 2016-2020 National Inpatient Sample (NIS) database whilst adjusting for confounders via logistic regression models. RESULTS: A total of 7,935 patients with CS were included in the study. The propensity-matched sample comprised of 5,570 patients, of whom 2,785 were White and 2,785 were AA. AA patients had a longer mean length of hospital stay (LOS) (7.84 vs. 6.94, p<0.01), a higher mean Charlson Comorbidity Index (CCI) score (3.10 vs. 2.84, p<0.01), and significantly higher incidences of cardiogenic shock [(9.2% vs 6.3%, p<0.01), aOR 1.45 (95% CI 1.17-1.78), p<0.01] and acute kidney injury (AKI) [(34.3% vs. 26.9%, p<0.01), aOR 1.41 (95% CI 1.24-1.61), p<0.01]. From an arrhythmia perspective, AA CS patients were shown to have a lower frequency of: (1) ventricular tachycardia (32.5% vs. 37.9%, p<0.01), (2) ventricular fibrillation (5.4% vs.7.2%, p<0.01), (3) first-degree AV block (1.8% vs. 4.1%, p<0.01), (4) complete AV block (6.3% vs. 14.2%, p<0.01), and (5) atrial fibrillation (31.8% vs. 34.8%, p=0.016) when compared to Whites with CS. Mortality remained higher for AAs (3.8% vs. 2.7%, p=0.024). CONCLUSION: Our study demonstrates a higher incidence of cardiac arrhythmias among White patients but a higher incidence of cardiogenic shock, AKI, mean LOS, and mortality among AA patients with cardiac sarcoidosis.

Surgical management of atrial fibrillation in patients undergoing cardiac surgery: a systematic review of clinical practice guidelines and recommendations.

AIMS: Surgical ablation of atrial fibrillation (AF) has been demonstrated to be a safe procedure conducted concomitantly alongside cardiac surgery. However, there are conflicting guideline recommendations surrounding indications for surgical ablation. We conducted a systematic review of current recommendations on concomitant surgical AF ablation. METHODS AND RESULTS: We identified publications from MEDLINE and EMBASE between January 2011 and December 2022 and additionally searched Guideline libraries and websites of relevant organizations in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 895 studies screened, 4 were rigorously developed (AGREE-II > 50%) and included. All guidelines agreed on the definitions of paroxysmal, persistent, and longstanding AF based on duration and refraction to current treatment modalities. In the Australia-New Zealand (CSANZ) and European (EACTS) guidelines, opportunistic screening for patients >65 years is recommended. The EACTS recommends systematic screening for those aged >75 or at high stroke risk (Class IIa, Level B). However, this was not recommended by American Heart Association or Society of Thoracic Surgeons guidelines. All guidelines identified surgical AF ablation during concomitant cardiac surgery as safe and recommended for consideration by a Heart Team with notable variation in recommendation strength and the specific indication (three guidelines fail to specify any indication for surgery). Only the STS recommended left atrial appendage occlusion (LAAO) alongside surgical ablation (Class IIa, Level C). CONCLUSION: Disagreements exist in recommendations for specific indications for concomitant AF ablation and LAAO, with the decision subject to Heart Team assessment. Further evidence is needed to develop recommendations for specific indications for concomitant AF procedures and guidelines need to be made congruent.

Predictors of morbidity and in-hospital mortality following procedure-related cardiac tamponade.

Background: Cardiac tamponade (CT) can be a complication following invasive cardiac procedures. We assessed CT following common cardiac electrophysiology (EP) procedures to facilitate risk prediction of associated morbidity and in-hospital mortality. Methods: Patients who underwent various EP procedures in the cardiac catheterization lab (ablations and device implantations) were identified using the International Classification of Diseases, Ninth and Tenth Edition, Clinical Modification (ICD-9-CM and ICD-10-CM, respectively) from the Nationwide Inpatient Sample (NIS) database. Patient demographics, presence of comorbidities, CT-related events, and in-hospital death were also abstracted from the NIS database. Results: The frequency of CT-related events in patients with EP intervention from 2010 to 2017 ranged from 3.4% to 7.0%. In-hospital mortality related to CT-related events was found to be 2.2%. Increasing age was the only predictor of higher mortality in atrial fibrillation (AF) ablation and cardiac resynchronization therapy (CRT) groups (OR [95% CI]: AF ablation = 11.15 [1.70-73.34], p = .01; CRT = 1.41 [1.05-1.90], p = .02). Conclusions: In the real-world setting, CT-related events in EP procedures were found to be 3.4%-7.0% with in-hospital mortality of 2.2%. Older patients undergoing AF ablation were found to have higher mortality.

Revisiting Diagnosis and Treatment of Hypertrophic Cardiomyopathy: Current Practice and Novel Perspectives.

Sarcomeric hypertrophic cardiomyopathy (HCM) is a prevalent genetic disorder characterised by left ventricular hypertrophy, myocardial disarray, and an increased risk of heart failure and sudden cardiac death. Despite advances in understanding its pathophysiology, treatment options for HCM remain limited. This narrative review aims to provide a comprehensive overview of current clinical practice and explore emerging therapeutic strategies for sarcomeric HCM, with a focus on cardiac myosin inhibitors. We first discuss the conventional management of HCM, including lifestyle modifications, pharmacological therapies, and invasive interventions, emphasizing their limitations and challenges. Next, we highlight recent advances in molecular genetics and their potential applications in refining HCM diagnosis, risk stratification, and treatment. We delve into emerging therapies, such as gene editing, RNA-based therapies, targeted small molecules, and cardiac myosin modulators like mavacamten and aficamten, which hold promise in modulating the underlying molecular mechanisms of HCM. Mavacamten and aficamten, selective modulators of cardiac myosin, have demonstrated encouraging results in clinical trials by reducing left ventricular outflow tract obstruction and improving symptoms in patients with obstructive HCM. We discuss their mechanisms of action, clinical trial outcomes, and potential implications for the future of HCM management. Furthermore, we examine the role of precision medicine in HCM management, exploring how individualised treatment strategies, including exercise prescription as part of the management plan, may optimise patient outcomes. Finally, we underscore the importance of multidisciplinary care and patient-centred approaches to address the complex needs of HCM patients. This review also aims to encourage further research and collaboration in the field of HCM, promoting the development of novel and more effective therapeutic strategies, such as cardiac myosin modulators, to hopefully improve the quality of life and outcome of patients with sarcomeric HCM.

Health Care Resource, Economic, and Readmission Implications After Acute Decompensated Aortic Stenosis-A Nationwide Study.

Acute decompensated aortic stenosis (ADAS) is common. The cumulative burden of ADAS from a clinical, health care resource, and financial perspective is unknown. This study sought to assess the national impact of ADAS compared with electively treated, stable patients with aortic stenosis (non-ADAS). Using the National Readmissions Database between 2016 and 2019, patients with ADAS and non-ADAS were identified using International Classification of Diseases, Tenth Revision codes. Patients with ADAS were propensity-matched to non-ADAS patients (1:2) using age, gender, and Charlson co-morbidity index. We compared in-hospital mortality, length of stay (LOS), health care-associated costs, and 90-day readmission data between the 2 cohorts. A total of 51,498 propensity-matched patients were included in this study: median age 75 years, 64% men. The in-hospital mortality for ADAS was higher than non-ADAS (2.8% vs 1.5%, p <0.0001). The LOS during the index admission was longer for ADAS (9 [5 to 13] vs 4 [2 to 6] days, p <0.0001). The health care-associated costs per patient was greater for ADAS ($55,450.0 [41,860.4 to 74,500.7] vs $43,405.7 [34,218.5 to 56,034.8], p <0.0001). Readmission to hospital within 90 days was more frequent in ADAS (21.1 vs 16.8%, p <0.001). The in-hospital mortality during readmission was higher with ADAS (3.9% vs 2.8%, p = 0.004). The readmission LOS was longer with ADAS (4 [2 to 7] vs 3 [2 to 6] days, p <0.0001). In conclusion, ADAS imposes a significant burden clinically and financially and on health care resources compared with non-ADAS during the index admission and 90-day follow-up. There is an urgent need to predict ADAS and optimize the timing of aortic valve replacement to reduce the incidence and the burden associated with ADAS.

Sex-specific associations between daytime sleepiness, chronic diseases and mortality in obstructive sleep apnea.

Objective: Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA) and has been linked to adverse outcomes, albeit inconsistently. Furthermore, whether the prognostic impact of EDS differs as a function of sex is unclear. We aimed to assess the associations between EDS and chronic diseases and mortality in men and women with OSA. Methods: Newly-diagnosed adult OSA patients who underwent sleep evaluation at Mayo Clinic between November 2009 and April 2017 and completed the Epworth Sleepiness Scale (ESS) for assessment of perceived sleepiness (N = 14,823) were included. Multivariable-adjusted regression models were used to investigate the relationships between sleepiness, with ESS modeled as a binary (ESS > 10) and as a continuous variable, and chronic diseases and all-cause mortality. Results: In cross-sectional analysis, ESS > 10 was independently associated with lower risk of hypertension in male OSA patients (odds ratio [OR], 95% confidence interval [CI]: 0.76, 0.69-0.83) and with higher risk of diabetes mellitus in both OSA men (OR, 1.17, 95% CI 1.05-1.31) and women (OR 1.26, 95% CI 1.10-1.45). Sex-specific curvilinear relations between ESS score and depression and cancer were noted. After a median 6.2 (4.5-8.1) years of follow-up, the hazard ratio for all-cause death in OSA women with ESS > 10 compared to those with ESS ≤ 10 was 1.24 (95% CI 1.05-1.47), after adjusting for demographics, sleep characteristics and comorbidities at baseline. In men, sleepiness was not associated with mortality. Conclusion: The implications of EDS for morbidity and mortality risk in OSA are sex-dependent, with hypersomnolence being independently associated with greater vulnerability to premature death only in female patients. Efforts to mitigate mortality risk and restore daytime vigilance in women with OSA should be prioritized.

Interpreting Incidentally Identified Variants in Genes Associated With Heritable Cardiovascular Disease: A Scientific Statement From the American Heart Association.

Rapid advances in genetic technologies have led to expanding use of diagnostic, research, and direct-to-consumer exome and genome sequencing. Incidentally identified variants from this sequencing represent a significant and growing challenge to interpret and translate into clinical care and include variants in genes associated with heritable cardiovascular disease such as cardiac ion channelopathies, cardiomyopathies, thoracic aortic disease, dyslipidemias, and congenital/structural heart disease. These variants need to be properly reported, the risk of associated disease accurately assessed, and clinical management implemented to prevent or lessen the disease so that cardiovascular genomic medicine can become both predictive and preventive. The goal of this American Heart Association consensus statement is to provide guidance to clinicians who are called on to evaluate patients with incidentally identified genetic variants in monogenic cardiovascular disease genes and to assist them in the interpretation and clinical application of variants. This scientific statement outlines a framework through which clinicians can assess the pathogenicity of an incidental variant, which includes a clinical evaluation of the patient and the patient's family and re-evaluation of the genetic variant in question. Furthermore, this guidance underscores the importance of a multidisciplinary team to address these challenging clinical evaluations and highlights how clinicians can effectively interface with specialty centers.

Autonomic Cardiovascular Control in Health and Disease.

Autonomic neural control of the cardiovascular system is formed of complex and dynamic processes able to adjust rapidly to mitigate perturbations in hemodynamics and maintain homeostasis. Alterations in autonomic control feature in the development or progression of a multitude of diseases with wide-ranging physiological implications given the neural system's responsibility for controlling inotropy, chronotropy, lusitropy, and dromotropy. Imbalances in sympathetic and parasympathetic neural control are also implicated in the development of arrhythmia in several cardiovascular conditions sparking interest in autonomic modulation as a form of treatment. A number of measures of autonomic function have shown prognostic significance in health and in pathological states and have undergone varying degrees of refinement, yet adoption into clinical practice remains extremely limited. The focus of this contemporary narrative review is to summarize the anatomy, physiology, and pathophysiology of the cardiovascular autonomic nervous system and describe the merits and shortfalls of testing modalities available. © 2023 American Physiological Society. Compr Physiol 13:4493-4511, 2023.

Impact of Sleep Duration and Chronotype on Cardiac Structure and Function: The UK Biobank Study.

Sleep duration and chronotype have been associated with increased morbidity and mortality. We assessed for associations between sleep duration and chronotype on cardiac structure and function. UK Biobank participants with CMR data and without known cardiovascular disease were included. Self-reported sleep duration was categorized as short (<7 h/d), normal (7-9 h/d) and long (>9 h/d). Self-reported chronotype was categories as "definitely morning" or "definitely evening." Analysis included 3903 middle-aged adults: 929 short, 2924 normal and 50 long sleepers; with 966 definitely-morning and 355 definitely-evening chronotypes. Long sleep was independently associated with lower left ventricular (LV) mass (-4.8%, P = 0.035), left atrial maximum volume (-8.1%, P = 0.041) and right ventricular (RV) end-diastolic volume (-4.8%, P = 0.038) compared to those with normal sleep duration. Evening chronotype was independently associated with lower LV end-diastolic volume (-2.4%, P = 0.021), RV end-diastolic volume (-3.6%, P = 0.0006), RV end systolic volume (-5.1%, P = 0.0009), RV stroke volume (RVSV -2.7%, P = 0.033), right atrial maximal volume (-4.3%, P = 0.011) and emptying fraction (+1.3%, P = 0.047) compared to morning chronotype. Sex interactions existed for sleep duration and chronotype and age interaction for chronotype even after considering potential confounders. In conclusion, longer sleep duration was independently associated with smaller LV mass, left atrial volume and RV volume. Evening chronotype was independently associated with smaller LV and RV and reduced RV function compared to morning chronotype. Sex interactions exist with cardiac remodeling most evident in males with long sleep duration and evening chronotype. Recommendations for sleep chronotype and duration may need to be individualized based on sex.