Non-ECG-gated cardiac CT angiography in acute stroke is feasible and detects sources of embolism.

BACKGROUND: A significant portion of cryptogenic stroke is hypothesized to be secondary to cardiac embolism. However, transthoracic echocardiogram is usually delayed after stroke, and more detailed cardiac imaging is not routinely done. AIMS: This study aimed to determine whether non-ECG-gated cardiac CT angiography (cCTA) during hyperacute stroke would provide diagnostic quality images and act as an adjunct modality of cardiac imaging to detect sources of emboli. METHODS: In this single-center prospective cohort study, modified Code Stroke imaging was implemented with a 64-slice CT scanner, where the longitudinal axis of CT angiography was extended from the carina to the diaphragm. The primary outcomes of image quality, recruitment feasibility, impact on hyperacute time metrics, and additional radiation dose were assessed. Secondary outcomes consisted of detection of high-risk cardiac sources of embolism, mediastinal or lung pathology, and impact on etiologic classification. RESULTS: One hundred and twenty eligible patients were enrolled, of which 105 (87.5%) had good/moderate quality images for motion artifact and 119 (99.2%) for contrast opacification. Total CT time, door-to-needle time, and door-to-groin puncture time were unchanged with the addition of cCTA. Eighty-nine patients received a final diagnosis of ischemic stroke, of which 12/89 (13.5%) had high-risk cardioembolic findings on cCTA. Incidental findings, such as pulmonary embolism (PE) (7/89, 7.9%) and malignancy (6/89, 6.7%), were observed. cCTA led to changes in management for 19/120 (15.8%) of all patients, and reclassification of stroke etiology for 8/89 (9%) of patients. CONCLUSIONS: Non-ECG-gated cCTA can be feasibly incorporated into Code Stroke and provide diagnostic quality images without delays in hyperacute time metrics. It can detect high-risk cardiac sources, and other findings impacting patient care. This may help reclassify a subset of cryptogenic stroke cases and improve secondary prevention.

Impact of transcatheter aortic valve implantation on circulating von Willebrand factor in patients with severe aortic stenosis.

INTRODUCTION: Severe aortic stenosis (AS) can lead to degradation of high molecular weight (HMW) von Willebrand factor (VWF) which can result in haemostatic abnormalities. While studies have explored changes in VWF profiles before and after surgical aortic valve replacement (SAVR), the longer-term changes in VWF profiles pre- and post-transcatheter aortic valve implantation (TAVI) are less understood. AIM: Our primary objective was to identify differences in VWF multimer profiles and VWF function pre-TAVI and 1-month post-TAVI. Our secondary objective was to correlate VWF markers with measures of AS severity. METHODS: Adult patients with severe AS referred for TAVI at our institution were prospectively enrolled in this cohort study. Blood samples were collected for plasma analysis at three time points for all patients: 1 day pre-TAVI, 3 days post-TAVI, and 1-month post-TAVI. VWF antigen, activity, propeptide, collagen binding, multimers, and factor VIII coagulant activity were determined at each time point. Correlations between VWF parameters and severity of AS were assessed. RESULTS: Twenty participants (15 males, five females) with severe AS were recruited for the study. There was a significant increase in HMW VWF between pre-procedure and 1-month post-TAVI (p < .05). There was a transient increase in VWF antigen levels and activity at 3-days post TAVI that decreased to pre-TAVI levels at 1-month. There were no statistically significant correlations between VWF markers and AS severity. CONCLUSIONS: This is the first study to elucidate longer-term (>1 week) improvements in HMW VWF after a TAVI procedure in severe AS patients.

Evaluation of the Impact of an Echocardiographic Diagnosis of Pulmonary Hypertension on Patient Outcomes.

BACKGROUND: Although detection of elevated right ventricular systolic pressure (RVSP) on routine echocardiography is common, its clinical significance is underappreciated. The recent change in the hemodynamic definition of pulmonary hypertension (PH) lowering the threshold from mean pulmonary arterial pressure ≥ 25 mm Hg to > 20 mm Hg further clouds the picture. METHODS: A retrospective cohort study was performed on residents of the South East Local Health Integration Network (population 495,000), Ontario, Canada, who underwent transthoracic echocardiography at the Kingston Health Sciences Centre between February 19, 2013, and December 31, 2016. The index echocardiography from 9291 unique patients was obtained. RESULTS: A total of 2049 patients (22.1%) had an RVSP ≥ 40 mm Hg, 2040 patients (22.0%) had an RVSP ≥ 30 and < 40 mm Hg, but only 284 patients (3.1%) had a clinical diagnosis of PH. Although patients with an RVSP ≥ 40 mm Hg had the highest Charlson Comorbidity Index (CCI) (1.81 ± 0.05) and number of hospitalizations 1 year before the echocardiography (1.24 ± 0.03), patients with RVSP between 30 and 40 mm Hg also had significantly higher CCI (1.19 ± 0.04) and hospitalization (0.87 ± 0.03) compared with the CCI (0.84 ± 0.03) and hospitalization (0.65 ± 0.02) of patients with RVSP < 30 mm Hg (P < 0.0001). CONCLUSION: Despite the finding that an elevated RVSP ≥ 30 mm Hg is common and predicts adverse outcomes, most patients with elevated RVSP are not reported as having PH or investigated. The significance of the elevated RVSP is underappreciated.

CONTEXTE: Bien qu'une pression systolique ventriculaire droite (PSVD) élevée soit fréquemment mise en évidence au cours d'une échocardiographie systématique, sa portée clinique s'avère sous-estimée. La modification récente de la définition hémodynamique de l'hypertension pulmonaire (HP), faisant passer le seuil de la pression artérielle pulmonaire moyenne de ≥ 25 mmHg à > 20 mmHg, embrouille davantage la situation. MÉTHODOLOGIE: Une étude rétrospective a été réalisée au sein d'une cohorte de résidents du territoire du Réseau local d'intégration des services de santé du Sud-Est (population de 495 000 personnes) de l'Ontario (Canada) ayant subi une échocardiographie transthoracique au Centre des sciences de la santé de Kingston entre le 19 février 2013 et le 31 décembre 2016. L'échocardiographie de référence de 9 291 patients différents a été obtenue. RÉSULTATS: La PSVD était ≥ 40 mmHg chez 2 049 patients (22,1 %) et ≥ 30 et < 40 mmHg chez 2 040 patients (22,0 %), mais un diagnostic clinique d'HP n'avait été posé que chez 284 patients (3,1 %). L'indice de comorbidité de Charlson (ICC) le plus élevé (1,81 ± 0,05) et le plus grand nombre d'hospitalisations un an avant l'échocardiographie (1,24 ± 0,03) ont été notés chez les patients qui présentaient une PSVD ≥ 40 mmHg; néanmoins, les valeurs de ces paramètres se sont aussi révélées significativement plus élevées chez les patients affichant une PSVD allant de 30 à 40 mmHg (ICC : 1,19 ± 0,04; hospitalisations : 0,87 ± 0,03) comparativement aux patients présentant une PSVD < 30 mmHg (ICC : 0,84 ± 0,03; hospitalisations : 0,65 ± 0,02) (p < 0,0001). CONCLUSION: Malgré le fait qu'une PSVD élevée (≥ 30 mmHg) soit d'observation courante et prédictive de résultats cliniques défavorables, la plupart des cas ne sont pas signalés en tant que manifestation d'HP et ne font l'objet d'aucune investigation. La portée d'une PSVD élevée s'avère sous-estimée.

Feasibility and Reliability of Nonexpert POCUS for Cardiovascular Preparticipation Screening of Varsity Athletes: The SHARP Protocol.

BACKGROUND: Point of care ultrasound (POCUS) is a potential adjunctive cardiovascular preparticipation screening modality for young competitive athletes. A novel cardiac POCUS screening protocol, Screening the Heart of the Athlete Research Program (SHARP), was developed for nonexpert examiners to assess common structural etiologies associated with sudden cardiac arrest/death (SCA/D). METHODS: Assessment of primary outcomes of feasibility, and reliability of obtained measurements, performed by comparison to formal transthoracic echocardiogram was undertaken. Inter-rater reliability was based on Intraclass correlation coefficients (ICC) defined as moderate for 0.40 to 0.59, good for 0.60 to 0.79, and excellent for 0.80 or greater. Electrocardiograms (ECGs) were also obtained. Identification of disease or other abnormalities was a secondary outcome. RESULTS: Fifty varsity athletes at our institution underwent the SHARP protocol, with 19 undergoing formal transthoracic echocardiogram and ECG for comparison. POCUS image quality was good to excellent. Feasibility of assessing for hypertrophic cardiomyopathy, aortic root dilatation, and left-ventricular function was deemed highly possible but limited in 20% for right-ventricular assessment. Reliability was good for measurements of interventricular septal thickness (0.67), end diastolic left-ventricular diameter (0.61), aortic root diameter (0.63), and moderate for left-ventricular posterior wall thickness (0.42). No cardiovascular abnormalities were detected. CONCLUSIONS: A novel, comprehensive SHARP POCUS protocol performed by nonexpert practitioners demonstrated feasibility and reliability to assess varsity level athletes for common structural etiologies associated with SCA/D. Further large athlete screening cohort studies are required to validate the SHARP protocol and the role of cardiac POCUS as a screening modality.

Reverse atrial electrical remodeling induced by cardiac resynchronization therapy.

PURPOSE: Cardiac resynchronization therapy (CRT) has been shown to improve left atrial function; however the effect on reverse electrical remodeling has been poorly evaluated. We hypothesized that CRT might induce reverse atrial electrical remodeling manifesting in the surface ECG as a shortening in P-wave duration. METHODS: Patients with CRT and more than 92% biventricular pacing at minimum follow-up of 1 year were included in the analysis. Those with prior history of atrial fibrillation (AF) were excluded. Data were recorded for clinical, echocardiographic and ECG variables prior to implant and at least 12 months post implantation. Semiautomatic calipers and scanned ECGs at 300 DPI maximized × 8 were used to measure P-wave duration and diagnose advanced interatrial block (aIAB) during sinus rhythm. The occurrence of AF was assessed through analyses of intracardiac electrograms and clinical presentations. RESULTS: 41 patients were included in the study with mean age of 67.4 ±9.6 years, 71% were male, left atrial diameter 41.1 ± 8.5 mm and LV EF 28.5 ± 6.5%. Over a mean follow up of 55 months, a significant reduction in P-wave duration (142.7 ms vs. 133.1 ms; p < 0.001) was noted. The presence of aIAB was significantly reduced (36% vs. 17%; p = 0.03). The incidence of new onset AF was 36%. Time to AF onset after CRT implantation was not influenced by a reduction in P-wave duration. CONCLUSION: CRT induces atrial reverse electrical remodeling manifested as a reduction in P-wave duration. Larger studies are needed to determine the impact on AF incidence after CRT implantation.

Impact of methanol intoxication on the human electrocardiogram.

BACKGROUND: Methanol is a common commercial compound that can lead to significant morbidity and mortality with high levels of exposure. The purpose of this study was to describe electrocardiographic (ECG) changes associated with methanol intoxication. METHODS: A retrospective chart review was conducted with data from Kingston General Hospital collected between 2006 and 2011. Patient data, including demographics, medications, and laboratory data were recorded. Twelve-lead ECGs were obtained and changes were noted in relation to timing and extent of methanol intoxication. RESULTS: Nine patients with a mean age of 45 years were analyzed. All patients ingested methanol orally and presented to hospital between < 1 to 25 h after ingestion. The mean plasma methanol concentration on admission was 49.8 mmol/L. A lower pH and higher plasma methanol concentration were associated with multiple ECG changes. On admission, ECG changes included sinus tachycardia (44%), PR prolongation (11%), QTc prolongation (22%) and non-specific T-wave changes (66%). One patient developed a type-1 Brugada ECG pattern. During their course in hospital, 7 patients required dialysis, 3 required mechanical ventilation, 3 developed visual impairment, and 1 died. All ECG changes normalized while in hospital. CONCLUSIONS: Methanol intoxication can lead to several ECG changes with sinus tachycardia and non-specific T-wave changes being the most common. These changes were more prominent in cases of severe acidosis.