The diagnostic role of T wave morphology biomarkers in congenital and acquired long QT syndrome: A systematic review.

INTRODUCTION: QTc prolongation is key in diagnosing long QT syndrome (LQTS), however 25%-50% with congenital LQTS (cLQTS) demonstrate a normal resting QTc. T wave morphology (TWM) can distinguish cLQTS subtypes but its role in acquired LQTS (aLQTS) is unclear. METHODS: Electronic databases were searched using the terms "LQTS," "long QT syndrome," "QTc prolongation," "prolonged QT," and "T wave," "T wave morphology," "T wave pattern," "T wave biomarkers." Whole text articles assessing TWM, independent of QTc, were included. RESULTS: Seventeen studies met criteria. TWM measurements included T-wave amplitude, duration, magnitude, Tpeak-Tend, QTpeak, left and right slope, center of gravity (COG), sigmoidal and polynomial classifiers, repolarizing integral, morphology combination score (MCS) and principal component analysis (PCA); and vectorcardiographic biomarkers. cLQTS were distinguished from controls by sigmoidal and polynomial classifiers, MCS, QTpeak, Tpeak-Tend, left slope; and COG x axis. MCS detected aLQTS more significantly than QTc. Flatness, asymmetry and notching, J-Tpeak; and Tpeak-Tend correlated with QTc in aLQTS. Multichannel block in aLQTS was identified by early repolarization (ERD30% ) and late repolarization (LRD30% ), with ERD reflecting hERG-specific blockade. Cardiac events were predicted in cLQTS by T wave flatness, notching, and inversion in leads II and V5 , left slope in lead V6 ; and COG last 25% in lead I. T wave right slope in lead I and T-roundness achieved this in aLQTS. CONCLUSION: Numerous TWM biomarkers which supplement QTc assessment were identified. Their diagnostic capabilities include differentiation of genotypes, identification of concealed LQTS, differentiating aLQTS from cLQTS; and determining multichannel versus hERG channel blockade.

Acute Myocarditis and Pericarditis After mRNA COVID-19 Vaccinations-A Single-Centre Retrospective Analysis.

BACKGROUND: With the rapid rollout of COVID-19 vaccinations, numerous associated and suspected adverse events have been reported nationally and worldwide. Literature reporting confirmed cases of pericarditis and myocarditis following SARS-CoV-2 mRNA vaccinations has evolved, with a predominance in adolescent males following the second dose. METHODS: This was a retrospective analysis of all patients presenting to St Vincent's Hospital, Sydney, Australia with suspected COVID-19 vaccine-related myocarditis and pericarditis. The Brighton Collaboration Case Definitions of Myocarditis and Pericarditis were used to categorise patients into groups based on diagnostic certainty. Cardiac magnetic resonance imaging findings were reviewed against updated Lake Louise Criteria for diagnosing patients with suspected myocarditis. RESULTS: We report 10 cases of confirmed, possible or probable myocarditis and pericarditis. The mean age of presentation in the vaccine group was 33±9.0 years. The most common presenting symptom was pleuritic chest pain (n=8, 80%). Eight patients (80%) had electrocardiogram (ECG) abnormalities (n=6 pericarditis, n=2 myocarditis). Five patients (50%) had a minimum 24 hours of cardiac monitoring. One patient had multisystem inflammatory syndrome following vaccination (MIS-V) with severely impaired left ventricular ejection fraction and required admission to the intensive care unit. DISCUSSION AND CONCLUSION: Cardiac complications post mRNA vaccines are rare. Our case series reflects the worldwide data that vaccine-related myocarditis and pericarditis most frequently occur in young males, following the second dose of the vaccine. These cardiac side effects are mild and self-limiting, with adequate responses to oral anti-inflammatories. One patient developed a severe reaction, with no fatal cases.

Measurement and Management of QT Interval Prolongation for General Physicians.

One of the more challenging aspects of ECG interpretation is measurement and interpretation of the QT interval. This interval represents the time taken for the ventricles to completely repolarise after activation. Abnormal prolongation of the QT interval can lead to torsades de pointes, a form of potentially life-threatening polymorphic ventricular tachycardia (VT). Detection of a prolonged QT interval is essential as this can be a reversible problem, particularly in the context of the use of a variety of commonly prescribed medications in the hospital setting. Automated ECG printouts cannot be relied upon to diagnose QT interval prolongation; thus, the onus is on the clinician to identify it. This is a difficult task, as the normal QT interval is typically measured relative to the heart rate. Therefore, the QT interval often requires "correction" for the current heart rate, in order to correctly stratify the risk of torsades de pointes. A wealth of correctional formulae have been derived, but none has proven superior. We present an approach to the ECG in this context, and a step-by-step guide to manually measuring and correcting the QT interval, and an approach to management in common hospital-based clinical scenarios.

Open versus Endovascular Repair of Arch and Descending Thoracic Aneurysms: A Retrospective Comparison.

BACKGROUND: Thoracic aortic aneurysms (TAAs) contribute significant mortality if left untreated, but surgical repair has historically carried substantial risks. METHODS: We sought to observe trends and outcomes of open and endovascular thoracic endovascular aneurysm repair thoracic aortic repairs, so conducted a retrospective review of all patients who presented for management of TAAs from 2003 to 2013 at 2 hospitals in Sydney, Australia. RESULTS: A total of 179 patients presented with TAAs over the study period, including 5 ruptures. Fifty-two were treated nonoperatively, with 127 surgically repaired. Operative duration was significantly shorter in endovascular than open repair of arch (193 ± 108 vs. 396 ± 98 min, P = 0.0001) and descending aneurysms (242 ± 116 vs. 422.5 ± 161 min, P = 0.003). There were no differences in mortality or complication rates (including paraplegia), duration of hospital or intensive care unit stay, or transfusion requirements between endovascular and open TAA repairs. CONCLUSIONS: Apart from reduced surgical duration, this study revealed no benefits of endovascular over open TAA repair. Overall morbidity and mortality were low, even in elderly patients.

Rotator cuff muscles perform different functional roles during shoulder external rotation exercises.

The aim of this study was to compare activity in shoulder muscles during an external rotation task under conditions of increasing arm support to investigate whether changing support requirements would influence muscle recruitment levels, particularly in the rotator cuff (RC) muscles. Electromyographic recordings were collected from seven shoulder muscles using surface and indwelling electrodes. The dominant shoulder of 14 healthy participants were examined during dynamic shoulder external rotation performed at 90° abduction with the arm fully supported, partially supported, and unsupported. Linear regressions between arm support load and the averaged muscle activity across participants for each muscle showed infraspinatus predominantly contributing to rotating the shoulder whilst supraspinatus, deltoid, upper trapezius, and serratus anterior were predominantly functioning in support/stabilization roles. During dynamic shoulder external rotation in mid-range abduction, the RC muscles perform different functional roles. Infraspinatus is responsible for producing external rotation torque, supraspinatus is playing a larger joint stabilizer role, and subscapularis is contributing minimally to joint stability. The results also indicate that increasing support load requirements during an external rotation task may be a functionally specific way to retrain the stabilization function of axioscapular muscles. Manipulating joint stabilization requirements while maintaining constant rotational load is a novel method of investigating the differential contribution of muscles to joint movement and stabilization during a given task.

Epidemiology of infective endocarditis before versus after change of international guidelines: a systematic review.

INTRODUCTION: All major international guidelines for the management of infective endocarditis (IE) have undergone major revisions, recommending antibiotic prophylaxis (AP) restriction to high-risk patients or foregoing AP completely. We performed a systematic review to investigate the effect of these guideline changes on the global incidence of IE. METHODS: Electronic database searches were performed using Ovid Medline, EMBASE and Web of Science. Studies were included if they compared the incidence of IE prior to and following any change in international guideline recommendations. Relevant studies fulfilling the predefined search criteria were categorized according to their inclusion of either adult or pediatric patients. Incidence of IE, causative microorganisms and AP prescription rates were compared following international guideline updates. RESULTS: Sixteen studies were included, reporting over 1.3 million cases of IE. The crude incidence of IE following guideline updates has increased globally. Adjusted incidence increased in one study after European guideline updates, while North American rates did not increase. Cases of IE with a causative pathogen identified ranged from 62% to 91%. Rates of streptococcal IE varied across adult and pediatric populations, while the relative proportion of staphylococcal IE increased (range pre-guidelines 16-24.8%, range post-guidelines 26-43%). AP prescription trends were reduced in both moderate and high-risk patients following guideline updates. DISCUSSION: The restriction of AP to only high-risk patients has not resulted in an increase in the incidence of streptococcal IE in North American populations. The evidence of the impact of AP restriction on IE incidence is still unclear for other populations. Future population-based studies with adjusted incidence of IE, AP prescription rates and accurate pathogen identification are required to delineate findings further in these other regions.

Mobile Phone Technologies in the Management of Ischemic Heart Disease, Heart Failure, and Hypertension: Systematic Review and Meta-Analysis.

BACKGROUND: Cardiovascular disease (CVD) remains the leading cause of death worldwide. Mobile phones have become ubiquitous in most developed societies. Smartphone apps, telemonitoring, and clinician-driven SMS allow for novel opportunities and methods in managing chronic CVD, such as ischemic heart disease, heart failure, and hypertension, and in the conduct and support of cardiac rehabilitation. OBJECTIVE: A systematic review was conducted using seven electronic databases, identifying all relevant randomized control trials (RCTs) featuring a mobile phone intervention (MPI) used in the management of chronic CVD. Outcomes assessed included mortality, hospitalizations, blood pressure (BP), and BMI. METHODS: Electronic data searches were performed using seven databases from January 2000 to June 2019. Relevant articles were reviewed and analyzed. Meta-analysis was performed using standard techniques. The odds ratio (OR) was used as a summary statistic for dichotomous variables. A random effect model was used. RESULTS: A total of 26 RCTs including 6713 patients were identified and are described in this review, and 12 RCTs were included in the meta-analysis. In patients with heart failure, MPIs were associated with a significantly lower rate of hospitalizations (244/792, 30.8% vs 287/803, 35.7%; n=1595; OR 0.77, 95% CI 0.62 to 0.97; P=.03; I2=0%). In patients with hypertension, patients exposed to MPIs had a significantly lower systolic BP (mean difference 4.3 mm Hg; 95% CI -7.8 to -0.78 mm Hg; n=2023; P=.02). CONCLUSIONS: The available data suggest that MPIs may have a role as a valuable adjunct in the management of chronic CVD.

Safety and efficacy of aerobic exercise commenced early after cardiac surgery: A systematic review and meta-analysis.

BACKGROUND: Aerobic exercise is a critical component of cardiac rehabilitation following cardiac surgery. Aerobic exercise is traditionally commenced 2-6 weeks following hospital discharge and most commonly includes stationary cycling or treadmill walking. The initiation of aerobic exercise within this early postoperative period not only introduces the benefits associated with aerobic activity sooner, but also ameliorates the negative effects of immobilization associated with the early postoperative period. METHODS: A systematic review identified all studies reporting safety and efficacy outcomes of aerobic exercise commenced within two weeks of cardiac surgery. A meta-analysis was performed comparing functional, aerobic and safety outcomes in patients receiving early postoperative aerobic exercise compared with usual postoperative care. RESULTS: Six-minute walk test distance at hospital discharge was 419 ± 88 m in early aerobic exercise patients versus 341 ± 81 m in those receiving usual care (mean difference 69.5 m, 95% confidence interval (CI) 39.2-99.7 m, p < 0.00001). Peak aerobic power was 18.6 ± 3.8 ml·kg-1·min-1 in those receiving early exercise versus 15.0 ± 2.1 ml·kg-1·min-1 in usual care (mean difference 3.20 ml·kg-1·min-1, 95% CI 1.45-4.95, p = 0.0003). There was no significant difference in adverse events rates between the two groups (odds ratio 0.41, 95% CI 0.12-1.42, p = 0.16). CONCLUSION: Aerobic exercise commenced early after cardiac surgery significantly improves functional and aerobic capacity following cardiac surgery. While adverse event rates did not differ significantly, patients included were very low risk. Further studies are required to adequately assess safety outcomes of aerobic exercise commenced early after cardiac surgery.

Complex disease management of pregnant young patient with familial hypercholesterolaemia complicated by coronary artery disease and cerebrovascular disease.

Inherited disorders of lipid metabolism may cause a heavy burden of cardiovascular disease early in life. Familial hypercholesterolaemia (FH) with abnormalities of LDL metabolism results in marked LDL elevations and accelerated, multivessel atherosclerosis presenting in teenage or young adulthood. We describe the case of a 33-year-old woman who presented with exertional angina in the setting of pregnancy who was found post-partum to have severe triple-vessel disease including left main disease on coronary angiography (Figs. 1 and 2). She was also noted to have a typical supravalvular "hourglass" [1] abnormality of the aortic root (Fig. 3), and heavy calcification of the proximal aorta precluding conventional aortic cross clamping and bypass surgery. After discussion with the multidisciplinary team, her disease was felt to be amenable to a beating-heart coronary bypass technique with an anaortic approach to minimise the possibility of cerebral embolism. Significant extracranial cerebrovascular disease, a major risk for cardiopulmonary bypass, reinforced the beating-heart technique. Her ongoing management has consisted of medical therapy with cessation of breast feeding, statins, ezetimibe, and introduction of PCSK9-inhibitor therapy. This case illustrates a number of the difficulties associated with management of widespread atherosclerotic disease associated with FH, in which an excellent outcome was achieved with the assistance of a multi-disciplinary team.

Anatomical variations of the renal arterial vasculature: An Australian perspective.

INTRODUCTION: Variations of the renal arteries have been studied and published across various population groups, but similar information for the ethnically diverse nation of Australia is lacking. This study describes the pattern of renal artery anomalies in a section of the Australian population based on computed tomography (CT) angiograms of the abdomen and cadaveric dissection. METHODS: The renal arterial vasculature of 594 kidneys from 300 subjects (28 cadavers, 272 CT) was studied. The number and pattern of renal arteries were categorised on the basis of laterality, point of origin and termination in the kidney (superior pole, hilum and inferior pole), symmetry and sex. RESULTS: Multiple renal arteries were discovered in 22% of subjects and 12.12% of kidneys. The most common pattern observed was the presence of one variant renal artery (93.1%), compared to the finding of two (5.6%) and three (1.4%) multiple arteries. The aorta was the most frequent site of origin for anomalous vessels, while the hilum was the predominant point of entry. No significant difference was established between left- and right-sided kidneys (13.8% vs. 12.5%; P = 0.627); however, unilateral distribution was more common than bilateral additional renal arteries (16.7% vs. 3.4%; P < 0.01), and variations among males were more than females (27.2% vs. 15.2%; P < 0.05). A higher rate of multiple renal arteries was noted in cadaveric dissections compared to CT images (46.4% vs. 19.5%; P < 0.01). CONCLUSION: These findings provide application of an evidence-based teaching tool that facilitates education regarding renal arterial variations in Australia.