Causal Link between Ventricular Ectopy and Concussion.

We present a unique case study report of a male individual with a history of mild nonischaemic cardiomyopathy, with no ventricular ectopy, that at the age of 76 years sustained multiple concussions (i.e., mild traumatic brain injury) within a week of each other. Concussion symptoms included cognitive difficulties, "not feeling well," lethargy, fatigue, and signs of depression. He was later medically diagnosed with postconcussion syndrome. The patient, WJT, was referred for cardiac and neurological assessment. Structural neuroimaging of the brain (MRI) was unremarkable, but electrocardiography (ECG) assessments using a 24-hour Holter monitor revealed significant incidence of ventricular ectopy (9.4%; 9,350/99,836 beats) over a period of 5-6 months after injury and then a further increase in ventricular ectopy to 18% (15,968/88,189 beats) during the subsequent 3 months. The patient was then prescribed Amiodarone 200 mg, and his ventricular ectopy and concussion symptoms completely resolved simultaneously within days. To the authors' knowledge, our study is the first to show a direct link between observable and documented cardiac dysregulation and concussion symptomology. Our study has important implications for both cardiac patients and the patients that sustain a concussion, and if medically managed with appropriate pharmacological intervention, it can reverse ventricular ectopy and concussion symptomology. More research is warranted to investigate the mechanisms for this dramatic and remarkable change in cardiac and cerebral functions and to further explore the brain-heart interaction and the intricate autonomic interaction that exists between the extrinsic and intracardiac nervous systems.

Clinical Characteristics and Prognostic Factors of Myocarditis in New Zealand Patients.

BACKGROUND: Myocarditis is an inflammation of the heart muscle and an important cause of dilated cardiomyopathy. Its presentation is heterogeneous, and there are limited studies describing the clinical characteristics of these patients, or which factors predict adverse clinical outcomes. We performed a single-centre retrospective study to explore the clinical characteristics of patients with myocarditis. METHOD: Patients >15 years of age admitted to our centre with an ICD-10 diagnosis of myocarditis on their electronic discharge record between 2007 and 2016 were included. Clinical, biochemical and imaging factors were collected. The primary endpoint was combined major adverse cardiac events (MACE) consisting of all-cause mortality, decompensated heart failure leading to hospital admission, documented ventricular arrhythmia, recurrent myocarditis and heart transplantation. RESULTS: During this period, 178 patients were found to have a diagnosis of myocarditis (71% men, median age 39 years). Men were significantly younger than women (36 vs 53 years, U=4,543, p<0.001). ST-elevation on electrocardiogram was recorded in 59% of patients, and these patients were more likely to be male (85% vs 66%, p=0.012), younger (median age 32 vs 44 years, U=4,129, p=0.001) and to have chest pain (94% vs 65%, p<0.001). At a maximal follow-up of 8 years (mean 4.5 years), MACE occurred in 26 patients. MACE was associated with the presence of dyspnoea (26% vs 9%; hazard ratio [HR] 3.33, 95% confidence interval [CI] 1.53-7.28; p=0.003), pulmonary congestion on chest X-ray (54% vs 11%; HR 5.51; 95% CI 2.3-13.23; p<0.001), and left ventricular ejection fraction <50% on transthoracic echocardiography (24% vs 8%; HR 3.22; 95% CI 1.28-8.12; p=0.013). CONCLUSIONS: Myocarditis was more common in young men in our study. Factors associated with adverse outcomes in acute coronary syndromes were not seen in our younger population. Left ventricular dysfunction appears to be more important in predicting adverse outcomes in myocarditis.

ICare-ACS (Improving Care Processes for Patients With Suspected Acute Coronary Syndrome): A Study of Cross-System Implementation of a National Clinical Pathway.

BACKGROUND: Efforts to safely reduce length of stay for emergency department patients with symptoms suggestive of acute coronary syndrome (ACS) have had mixed success. Few system-wide efforts affecting multiple hospital emergency departments have ever been evaluated. We evaluated the effectiveness of a nationwide implementation of clinical pathways for potential ACS in disparate hospitals. METHODS: This was a multicenter pragmatic stepped-wedge before-and-after trial in 7 New Zealand acute care hospitals with 31 332 patients investigated for suspected ACS with serial troponin measurements. The implementation was a clinical pathway for the assessment of patients with suspected ACS that included a clinical pathway document in paper or electronic format, structured risk stratification, specified time points for electrocardiographic and serial troponin testing within 3 hours of arrival, and directions for combining risk stratification and electrocardiographic and troponin testing in an accelerated diagnostic protocol. Implementation was monitored for >4 months and compared with usual care over the preceding 6 months. The main outcome measure was the odds of discharge within 6 hours of presentation RESULTS: There were 11 529 participants in the preimplementation phase (range, 284-3465) and 19 803 in the postimplementation phase (range, 395-5039). Overall, the mean 6-hour discharge rate increased from 8.3% (range, 2.7%-37.7%) to 18.4% (6.8%-43.8%). The odds of being discharged within 6 hours increased after clinical pathway implementation. The odds ratio was 2.4 (95% confidence interval, 2.3-2.6). In patients without ACS, the median length of hospital stays decreased by 2.9 hours (95% confidence interval, 2.4-3.4). For patients discharged within 6 hours, there was no change in 30-day major adverse cardiac event rates (0.52% versus 0.44%; P=0.96). In these patients, no adverse event occurred when clinical pathways were correctly followed. CONCLUSIONS: Implementation of clinical pathways for suspected ACS reduced the length of stay and increased the proportions of patients safely discharged within 6 hours. CLINICAL TRIAL REGISTRATION: URL: https://www.anzctr.org.au/ (Australian and New Zealand Clinical Trials Registry). Unique identifier: ACTRN12617000381381.

Bias associated with left ventricular quantification by multimodality imaging: a systematic review and meta-analysis.

PURPOSE: Cardiac MR (CMR) is the gold standard for left ventricular (LV) quantification. However, two-dimensional echocardiography (2DE) is the most common approach, and both three-dimensional echocardiography (3DE) and multidetector CT (MDCT) are increasingly available. The clinical significance and interchangeability of these modalities remains under-investigated. Therefore, we undertook a systemic review to evaluate the accuracy and absolute bias in LV quantification of all the commonly available non-invasive imaging modalities (2DE, CE-2DE, 3DE, MDCT) compared to cardiac MR (CMR). METHODS: Studies were included that reported LV echocardiographic (2DE, CE-2DE, 3DE) and/or MDCT measurements compared to CMR. Only modern CMR (SSFP sequences) was considered. Studies involving small sample size (<10 patients) and unusual cardiac geometry (ie, congenital heart diseases) were excluded. We evaluated LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF). RESULTS: 1604 articles were initially considered: 65 studies were included (total of 4032 scans (echo, CT, MRI) performed in 2888 patients). Compared to CMR, significant biased underestimation of LV volumes with 2DE was seen (LVEDV-33.30 mL, LVESV -16.20 mL, p<0.0001). This difference was reduced but remained significant with CE-2DE (LVEDV -18.05, p<0.0001) and 3DE (LVEDV -14.41, p<0.001), while MDCT values were similar to CMR (LVEDV -1.20, p=0.43; LVESV -0.13, p=0.91). However, excellent agreement for echocardiographic LVEF evaluation (2DE LVEF 0.78-1.01%, p=0.37) was observed, especially with 3DE (LVEF 0.14%, p=0.88). CONCLUSIONS: Comparing imaging modalities to CMR as reference standard, 3DE had the highest accuracy in LVEF estimation: 2DE and 3DE-derived LV volumes were significantly underestimated. Newer generation CT showed excellent accuracy for LV volumes.

Determination of Clinical Outcome in Mitral Regurgitation With Cardiovascular Magnetic Resonance Quantification.

BACKGROUND: Surgery for severe mitral regurgitation is indicated if symptoms or left ventricular dilation or dysfunction occur. However, prognosis is already reduced by this stage, and earlier surgery on asymptomatic patients has been advocated if valve repair is likely, but identifying suitable patients for early surgery is difficult. Quantifying the regurgitation may help, but evidence for its link with outcome is limited. Cardiovascular magnetic resonance (CMR) can accurately quantify mitral regurgitation, and we examined whether this was associated with the future need for surgery. METHODS AND RESULTS: One hundred nine asymptomatic patients with echocardiographic moderate or severe mitral regurgitation had baseline CMR scans and were followed up for up to 8 years (mean, 2.5±1.9 years). CMR quantification accurately identified patients who progressed to symptoms or other indications for surgery: 91% of subjects with regurgitant volume ≤55 mL survived to 5 years without surgery compared with only 21% with regurgitant volume >55 mL (P<0.0001). A similar separation was observed for regurgitant fraction ≤40% and >40%. CMR-derived end-diastolic volume index showed a weaker association with outcome (proportions surviving without surgery at 5 years, 90% for left ventricular end-diastolic volume index <100 mL/m(2) versus 48% for ≥100 mL/m(2)) and added little to the discriminatory power of regurgitant fraction/volume alone. CONCLUSIONS: CMR quantification of mitral regurgitation was associated with the development of symptoms or other indications for surgery and showed better discriminatory ability than the reference-standard CMR-derived ventricular volumes. CMR may be able to identify appropriate patients for early surgery, with the potential to change clinical practice, although the clinical benefits of early surgery require confirmation in a clinical trial.

Evaluation of a New Zealand program to improve transition of care for older high risk adults.

Transition interventions aim to improve care and reduce hospital readmissions but evaluations of these interventions have reported inconsistent results. We report on the evaluation of an intervention implemented in Auckland, New Zealand. Participants were people over the age of 65 who had an acute medical admission and were at high risk of readmission. The intervention included an improved discharge process and nurse telephone follow-up soon after discharge. Outcomes were 28 day readmission rates and emergency attendances. The study is observational, using both interrupted times series and regression discontinuity designs. 5239 patients were treated over a one year period. There was no change in readmission rates or ED attendances or secondary outcomes. Not all patients received all components of the intervention. This transition intervention was not successful. Possible reasons for this and implications are discussed. Although non-experimental methods were used, we believe the results are robust.

Utility of cardiac magnetic resonance in the evaluation of unselected patients with possible arrhythmogenic right ventricular cardiomyopathy.

INTRODUCTION: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare but important cause of sudden cardiac death. We investigated the role of cardiac magnetic resonance imaging (CMR) in the evaluation of patients with suspected ARVC referred by a general cardiology service. METHODS: Ninety-two patients (mean age 48 ± 15, 49% female), referred for CMR assessment of possible ARVC, were reviewed. CMR included both functional and tissue characteristic imaging. RESULTS: No patients had ARVC based on the 1994 Task Force Criteria (TFC) prior to CMR, but 4 met proposed Modified TFC; 15% met one major (±1 minor) TFC, 71% 1 or 2 minor TFC, and 14% no TFC. Reasons for CMR referral included symptomatic arrhythmia of likely RV origin (28%), Electrocardiogram/Holter abnormalities (28%), echocardiographic features suspicious of ARVC (19%), and family history of ARVC (8%). CMR findings strongly suggestive of ARVC were found in nine patients (10%), although only three were considered typical. Of these patients two met 1 major TFC and seven met 1 or 2 minor TFC. CMR findings included RV thinning, aneurysm, and diastolic out-pouching, but only 1 patient had definite fatty infiltration of the RV. Incidentally, CMR detected important, previously undiagnosed pathology, including anomalous pulmonary venous drainage (2 patients) and non-ischaemic cardiomyopathy (6%). CMR was normal in 63%, with minor abnormalities in 29%. CONCLUSIONS: CMR may play an important diagnostic role in the evaluation of possible ARVC. Patients who do not meet TFC for diagnosis may have CMR features typical of ARVC. Additionally CMR may detect other hitherto undiagnosed structural or functional abnormalities that alter patient management. However the majority of patients referred have a low pretest probability of ARVC, and the rate of normal CMR scans is high.

Aortic regurgitation quantification using cardiovascular magnetic resonance: association with clinical outcome.

BACKGROUND: Current indications for surgery in patients with significant aortic regurgitation (AR) focus on symptoms and left ventricular dilation/dysfunction. However, prognosis is already reduced by this stage, and earlier identification of patients for surgery could be beneficial. Quantifying the regurgitation may help, but there are limited data on its link with outcome. Cardiovascular magnetic resonance (CMR) can accurately quantify AR, and we examined whether this was associated with the future need for surgery. METHODS AND RESULTS: One hundred thirteen patients with echocardiographic moderate or severe AR were monitored for up to 9 years (mean 2.6 ± 2.1 years) following a CMR scan, and the progression to symptoms or other indications for surgery was monitored. AR quantification identified outcome with high accuracy: 85% of the 39 subjects with regurgitant fraction >33% progressed to surgery (mostly within 3 years) in comparison with 8% of 74 subjects with regurgitant fraction ≤ 33% (P<0.0001); the area under the curve on receiver operating characteristic analysis was 0.93 (P<0.0001). This ability remained strong on time-dependent Kaplan-Meier survival curves. CMR-derived left ventricular end-diastolic volume >246 mL had good, although lower, discriminatory ability (area under the curve 0.88), but the combination of this measure with regurgitant fraction provided the best discriminatory power. CONCLUSIONS: High degrees of CMR-quantified AR were associated with the development of symptoms or other indications for surgery. Quantifying AR showed slightly better discriminatory ability than "gold standard" CMR ventricular volume assessment. This could provide a new paradigm for the timing of surgical intervention but requires confirmation in a clinical trial.

An uncommon cause of myocardial infarction.

A 73 year-old lady with hypertension and chronic atrial fibrillation (AF) developed chest pain followed by ventricular fibrillation (VF) cardiac arrest. Her electrocardiogram post-cardioversion revealed inferior ST-elevation myocardial infarction (MI). Her coronary arteries were angiographically normal. Contrast-enhanced cardiac magnetic resonance(CE-CMR) demonstrated both an inferior subendocardial infarction and left atrial (LA) appendage thrombus suggesting cardioembolism as the most likely cause of her presentation.

Assessment of valvular heart disease by cardiovascular magnetic resonance imaging: a review.

CMR is a comprehensive non-invasive tool capable of evaluating all aspects of valvular heart disease. It has advantages over echo including direct quantification of regurgitant lesions, highly accurate assessment of ventricular size and function, visualisation myocardial scar, and interrogation of extracardiac abnormalities. Although these gains can be realised with current scanning techniques, CMR's full potential has yet to be realised, and further studies of clinical outcomes are needed before CMR data can be integrated into the management algorithms for patients with significant valvular lesions.

Stress perfusion imaging using cardiovascular magnetic resonance: a review.

Stress perfusion CMR can provide both excellent diagnostic and important prognostic information in the context of a comprehensive assessment of cardiac anatomy and function. This coupled with the high spatial resolution, and the lack of both attenuation artefacts and ionising radiation, make CMR stress perfusion imaging a highly attractive stress imaging modality. It is now in routine use in many centres, and shows promise in evaluating patients with clinical problems beyond those of epicardial coronary disease.

Prevalence and prognostic significance of left ventricular dysfunction in patients presenting acutely with atrial fibrillation.

CONDENSED ABSTRACT: The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. This study investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes. We demonstrated that CM is common in patients presenting acutely with newly diagnosed rapid AF, and carries a worse long-term prognosis. Systolic dysfunction was reversible in an important proportion of patients, suggesting a greater prevalence of rate-related CM in AF than has previously been postulated. This underscores the importance of appropriate rhythm management strategies and repeat imaging studies. BACKGROUND: Atrial fibrillation (AF) may precipitate LV dysfunction, potentially leading to cardiomyopathy (CM). The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. We investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes. METHODS: We reviewed 292 consecutive patients (average age 72 +/- 13yrs) presenting acutely with AF and tachycardia over a 3 year period from June 2004. Clinical details were obtained from medical records. CM was defined as ejection fraction (EF)

Characteristics and prognostic importance of myocardial fibrosis in patients with dilated cardiomyopathy assessed by contrast-enhanced cardiac magnetic resonance imaging.

INTRODUCTION: Dilated cardiomyopathy (DCM) is associated with significant morbidity and mortality. Contrast-enhanced cardiac MRI (CE-CMR) can detect potentially prognostic myocardial fibrosis in DCM. We investigated the role of CE-CMR in New Zealand patients with DCM, both Maori and non-Maori, including the characteristics and prognostic importance of fibrosis. METHODS: One hundred and three patients (mean age 58 ± 13, 78 male) referred for CMR assessment of DCM were followed for 660 ± 346 days. Major adverse cardiac events (MACE) were defined as death, infarction, ventricular arrhythmias or rehospitalisation. CE-CMR used cines for functional analysis, and delayed enhancement to assess fibrosis. RESULTS: Myocardial fibrosis was present in 30% of patients, the majority of which was mid-myocardial (63%). Volumetric parameters were similar in patients with or without fibrosis. At 2 years patients with fibrosis had an increased rate of MACE (HR = 0.77, 95% CI 0.3-2.0). Patients with full thickness or subendocardial fibrosis had the highest MACE, even in the absence of CAD). More Maori had fibrosis on CE-CMR (40% vs. 28% for non-Maori), and the majority (75%) was mid-myocardial. Maori and non-Maori had similar outcomes (25% vs. 24% with events during follow-up). CONCLUSIONS: DCM patients frequently have myocardial fibrosis detected on CE-CMR, the majority of which is mid-myocardial. Fibrosis is associated with worse outcome in the medium term. The information obtained using CE-CMR in DCM may be of incremental clinical benefit.

Bartonella henselae aortic valve endocarditis mimicking systemic vasculitis.

A 28-year-old man with a bicuspid aortic valve presented with facial droop and slurred speech with several months of constitutional symptoms of night sweats, weight loss and productive cough. Examination confirmed aortic regurgitation, palpable spleen and left facial droop. Multiple peripheral blood cultures were negative. Inflammatory markers, cytoplasmic staining antineutrophil cytoplasmic antibodies (cANCA) and anti-PR3 antibody were all elevated. MRI of the brain and CT of the chest and abdomen confirmed embolic infarcts to brain, kidney and spleen. Transoesophageal echocardiogram (ECG) showed valve vegetations and severe aortic regurgitation. Endocardial Wegener's granulomatosis was considered. Aortic valve replacement was performed. Grindings from aortic valve leaflets were analysed for rpoB gene, which confirmed the presence of Bartonella henselae. Serological assays demonstrated B henselae IgM 20 (normal <20) and IgG >2048 (normal < 64). The patient completely recovered after prolonged antibiotic treatment. Culture-negative infective endocarditis may mimic vasculitis and be associated with positive cANCA. Serology and molecular techniques may aid diagnosis.

Myocardial scar detected by contrast-enhanced cardiac magnetic resonance imaging is associated with ventricular tachycardia in hypertrophic cardiomyopathy patients.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is associated with myocardial scarring and ventricular tachycardia (VT). Contrast-enhanced cardiac magnetic resonance imaging (CE-CMR) can quantify myocardial scar, and scar imaging has been documented in patients with HCM. We investigated the assessment of myocardial scar in HCM patients using CE-CMR, and its correlation with proven VT. METHODS: Twenty-five patients (mean age 54 +/- 8) with HCM who underwent CE-CMR were identified, and clinical data obtained from chart review. Parameters of LV function were calculated from cine imaging, and myocardial scar was assessed using delayed enhancement imaging following gadolinium administration. RESULTS: Myocardial scar was detected in 16 (64%) patients with a mean mass 9 +/- 15 g. Scar was patchy, mid-myocardial and located in the basal anteroseptum, and RV insertion sites. Scar was seen in septal, apical and concentric variants of HCM. Scar mass correlated with both LV Mass (r2 = 0.74) and maximal LV wall thickness (r2 = 0.42). VT occurred in 32% of patients, and was associated with both increased scar mass and wall thickness compared to non-VT patients (21 +/- 22 g vs. 4 +/- 6 g, and 2.4 +/- 0.5 cm vs. 1.8 +/- 0.5 cm, p < 0.05). LV size and function were similar in patients with and without VT. A scar mass of >7 g predicted the presence of VT with a sensitivity of 75% and specificity 82%. CONCLUSIONS: Myocardial scar imaged by CE-CMR is common in patients with HCM, and is predictive of VT. Scar is seen in all HCM variants, and is associated with maximal wall thickness. There may be a role for CE-CMR in improved risk stratification for individual patients with HCM.

Reliability of echocardiographic indices of dyssynchrony.

BACKGROUND: Echocardiographic indices of dyssynchrony are increasingly used to select candidates for cardiac resynchronization therapy. For widespread screening of heart failure patients, such variables need to be comparable when evaluated by different operators using different equipment. OBJECTIVE AND METHODS: To evaluate the reproducibility and obtainability of echocardiographic indices of mechanical dyssynchrony, we studied 40 subjects stratified according to QRS morphology and systolic function. Two echocardiograms were performed on each patient by different sonographers on different machines and each study was analyzed by two observers. RESULTS: All blood-pool and tissue Doppler indices of dyssynchrony were obtainable in over 97% of cases. Blood-pool Doppler measures were the most reproducible indices of intraventricular dyssynchrony (aortic ejection delay) and interventricular dyssynchrony (aortopulmonary difference in ejection delay). For annular tissue Doppler delays, the time to peak velocity was consistently more reproducible than the time to velocity onset. CONCLUSION: Differences in the reliability of echocardiographic indices may affect their suitability as screening tests for dyssynchrony.