Athletes and members of the public increasingly rely on wearable HR monitors to guide physical activity and training. The accuracy of newer, optically based monitors is unconfirmed. We sought to ...assess the accuracy of five optically based HR monitors during various types of aerobic exercise.
Fifty healthy adult volunteers (mean ± SD age = 38 ± 12 yr, 54% female) completed exercise protocols on a treadmill, a stationary bicycle, and an elliptical trainer (±arm movement). Each participant underwent HR monitoring with an electrocardiogaphic chest strap monitor (Polar H7), forearm monitor (Scosche Rhythm+), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, and TomTom Spark Cardio), one on each wrist. For each exercise type, HR was recorded at rest, light, moderate, and vigorous intensity. Agreement between HR measurements was assessed using Lin's concordance correlation coefficient (rc).
Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (rc = 0.996) followed by the Apple Watch (rc = 0.92), the TomTom Spark (rc = 0.83), and the Garmin Forerunner (rc = 0.81). Scosche Rhythm+ and Fitbit Blaze were less accurate (rc = 0.75 and rc = 0.67, respectively). On treadmill, all devices performed well (rc = 0.88-0.93) except the Fitbit Blaze (rc = 0.76). While bicycling, only the Garmin, Apple Watch, and Scosche Rhythm+ had acceptable agreement (rc > 0.80). On the elliptical trainer without arm levers, only the Apple Watch was accurate (rc = 0.94). None of the devices was accurate during elliptical trainer use with arm levers (all rc < 0.80).
The accuracy of wearable, optically based HR monitors varies with exercise type and is greatest on the treadmill and lowest on elliptical trainer. Electrode-containing chest monitors should be used when accurate HR measurement is imperative.
We performed a systematic review of the current state of the literature regarding the natural history and outcomes of bicuspid aortic valve (BAV). PubMed and the reference lists of the included ...articles were searched for relevant studies reporting on longitudinal follow-up of BAV cohorts (mean follow-up ≥2 years). Studies limited to patients undergoing surgical interventions were excluded. 13 studies (11 502 patients with 2-16 years of follow-up) met the inclusion criteria. There was a bimodal age distribution (30-40 vs ≥50 years), with a 3:1 male to female ratio. Complications included moderate to severe aortic regurgitation (prevalence 13%-30%), moderate to severe aortic stenosis (12%-37%), infective endocarditis (2%-5%) and aortic dilatation (20%-40%). Aortic dissection or rupture was rare, occurring in 38 patients (0.4%, 27/6446 in native BAV and 11/2232 in post). With current aggressive surveillance and prophylactic surgical interventions, survival in three out of four studies was similar to that of a matched general population. In this systematic review, valvular dysfunction warranting surgical intervention in patients with BAV were common, aortic dissection was rare and, with the current management approach, survival was similar to that of the general population.
Hypertrophic cardiomyopathy (HCM) is a heterogeneous genetic heart disease inherited in an autosomal dominant pattern with an estimated prevalence of 0.6% in the general population. Clinical ...manifestations of HCM vary considerably, with symptoms ranging from none or mild exercise intolerance to severe lifestyle-limiting symptoms, advanced heart failure, and sudden cardiac death. Current management options for HCM include lifestyle modifications, familial screening with genetic counseling, pharmacotherapy for symptom control, sudden cardiac death risk stratification with or without defibrillator implantation, septal reduction therapy, and, in some cases, heart transplantation. Only recently have strongly targeted medical therapies for HCM, such as myosin inhibitors, been studied in multicenter randomized controlled trials. In this report, we review the currently available medical treatments for HCM and the future directions of HCM pharmacotherapy, and we highlight important unmet needs in this population.
Coronary artery inflammation inhibits adipogenesis in adjacent perivascular fat. A novel imaging biomarker—the perivascular fat attenuation index (FAI)—captures coronary inflammation by mapping ...spatial changes of perivascular fat attenuation on coronary computed tomography angiography (CTA). However, the ability of the perivascular FAI to predict clinical outcomes is unknown.
In the Cardiovascular RISk Prediction using Computed Tomography (CRISP-CT) study, we did a post-hoc analysis of outcome data gathered prospectively from two independent cohorts of consecutive patients undergoing coronary CTA in Erlangen, Germany (derivation cohort) and Cleveland, OH, USA (validation cohort). Perivascular fat attenuation mapping was done around the three major coronary arteries—the proximal right coronary artery, the left anterior descending artery, and the left circumflex artery. We assessed the prognostic value of perivascular fat attenuation mapping for all-cause and cardiac mortality in Cox regression models, adjusted for age, sex, cardiovascular risk factors, tube voltage, modified Duke coronary artery disease index, and number of coronary CTA-derived high-risk plaque features.
Between 2005 and 2009, 1872 participants in the derivation cohort underwent coronary CTA (median age 62 years range 17–89). Between 2008 and 2016, 2040 patients in the validation cohort had coronary CTA (median age 53 years range 19–87). Median follow-up was 72 months (range 51–109) in the derivation cohort and 54 months (range 4–105) in the validation cohort. In both cohorts, high perivascular FAI values around the proximal right coronary artery and left anterior descending artery (but not around the left circumflex artery) were predictive of all-cause and cardiac mortality and correlated strongly with each other. Therefore, the perivascular FAI measured around the right coronary artery was used as a representative biomarker of global coronary inflammation (for prediction of cardiac mortality, hazard ratio HR 2·15, 95% CI 1·33–3·48; p=0·0017 in the derivation cohort, and 2·06, 1·50–2·83; p<0·0001 in the validation cohort). The optimum cutoff for the perivascular FAI, above which there is a steep increase in cardiac mortality, was ascertained as −70·1 Hounsfield units (HU) or higher in the derivation cohort (HR 9·04, 95% CI 3·35–24·40; p<0·0001 for cardiac mortality; 2·55, 1·65–3·92; p<0·0001 for all-cause mortality). This cutoff was confirmed in the validation cohort (HR 5·62, 95% CI 2·90–10·88; p<0·0001 for cardiac mortality; 3·69, 2·26–6·02; p<0·0001 for all-cause mortality). Perivascular FAI improved risk discrimination in both cohorts, leading to significant reclassification for all-cause and cardiac mortality.
The perivascular FAI enhances cardiac risk prediction and restratification over and above current state-of-the-art assessment in coronary CTA by providing a quantitative measure of coronary inflammation. High perivascular FAI values (cutoff ≥–70·1 HU) are an indicator of increased cardiac mortality and, therefore, could guide early targeted primary prevention and intensive secondary prevention in patients.
British Heart Foundation, and the National Institute of Health Research Oxford Biomedical Research Centre.
This study evaluates operative approach and contemporary surgical outcomes in the management of left ventricular outflow tract obstruction by a single surgeon at a high-volume, specialized ...hypertrophic cardiomyopathy center.
This is a retrospective review of 1559 consecutive operations for left ventricular outflow tract obstruction from 2005 to 2015. Demographic profiles, echocardiogram-derived ventricular morphology and hemodynamics, operative data, and in-hospital outcomes were analyzed.
Of the 1559 operations, 586 were isolated septal myectomies, 522 were myectomies with mitral valve or subvalvular apparatus intervention, 422 were myectomies with another concomitant procedure, and 29 were isolated mitral valve interventions without myectomy. Common mitral valve interventions included anterior leaflet shortening (16%), chordae tendineae resection (9.8%), papillary muscle resection (7.2%), and papillary muscle reorientation (7.5%). Ninety-two patients underwent mitral valve replacement, 42 for left ventricular outflow tract obstruction and 50 for intrinsic mitral valve pathology. Patients undergoing mitral interventions had thinner septums (18 ± 0.4 mm vs 22 ± 0.5 mm, P < .001) and less myocardium removed (6.2 ± 3.5 g vs 8.8 ± 3.8 g, P < .001) than patients without a mitral intervention. Prevalence of in-hospital permanent pacemaker insertion was 4.2% (n = 1334) for complete heart block and 1.1% (n = 464) for isolated septal myectomy with normal preoperative conduction. Overall, there were 2 postoperative ventricular septal defects (0.13%) and none for isolated myectomies. Operative mortality was 0.38%.
Septal myectomy can be performed safely with excellent outcomes when the procedure is performed by a highly experienced surgeon in a high-volume, specialized center. A mitral valve intervention is a useful adjunct in patients with moderate hypertrophy.
Hypertrophic cardiomyopathy (HCM) is predominantly an autosomal dominant genetic heart disease with an estimated prevalence of 1 in 200 to 1 in 500 in the general population. Clinical manifestations ...of HCM vary from asymptomatic state to mild functional intolerance to advanced heart failure, angina, and sudden cardiac death (SCD). Current management options for symptomatic HCM include lifestyle modifications, pharmacotherapy for symptom control and arrhythmia management, SCD risk stratification with or without defibrillator implantation, septal reduction therapy and, in some cases, heart transplantation. Until recently, none of the pharmacotherapies for management of HCM had been studied in multicenter randomized controlled trials. Mavacamten, a cardiac myosin inhibitor, is the first drug studied in this fashion and the first-in-class Food and Drug Administration approved medication that specifically targets the pathophysiology of HCM. We will review the currently available medical treatments for HCM and assess future directions.
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