Comparison of methods for correcting QT interval in athletes and young people: A systematic review.

Screening elite athletes for conditions associated with sudden cardiac death is recommended by numerous international guidelines. Current athlete electrocardiogram interpretation criteria recommend the Bazett formula (QTcB) for correcting QT interval. However, other formulae may perform better at lower and higher heart rates (HR). This review aimed to examine the literature on various QT correction methods in athletes and young people aged 14-35 years and determine the most accurate method of calculating QTc in this population. A systematic review of MEDLINE, EMBASE, Scopus, and SportDiscus was performed. Papers comparing at least two different methods of QT interval correction in athletes or young people were included. Quality and risk of bias were assessed using a standardized tool. The search strategy identified 545 papers, of which 10 met the criteria and were included. Nine of these studies concluded that QTcB was least reliable for removing the effect of HR and was inaccurate at both high (>90 beats per min [BPM]) and low (<60 BPM) HRs. No studies supported the use of QTcB in athletes and young people. Alternative QT correction algorithms such as Fridericia (QTcF) produce more accurate correction of QT interval at HRs seen in athletes and young people. QTcB is less accurate at lower and higher HRs. QTcF has been shown to be more accurate in these HR ranges and may be preferred to QTcB for QTc calculation in athletes and young people. However, accurate QTc reference values for discrete HRs using alternative algorithms are not well established and require further research.

Cardiovascular risk management in the peri-operative setting.

Peri-operative cardiovascular events occur in up to 3% of patients undergoing non-cardiac surgery. Accurate cardiovascular risk assessment is important in the peri-operative setting, as it allows informed and shared decisions regarding the appropriateness of proceeding with surgery, guides surgical and anaesthetic approaches, and may influence the use of preventive medications and post-operative cardiac monitoring. Quantitative risk assessment may also inform a reconsideration of choosing a more limited lower risk type of surgery, or conservative management. Pre-operative cardiovascular risk assessment starts with clinical assessment and should include an estimate of functional capacity. Specialised cardiac investigations are rarely indicated specifically to assess pre-operative cardiovascular risk. The decision regarding cardiac investigations is influenced by the nature, extent and urgency of surgery. The strategy of performing pre-operative revascularisation to improve post-operative outcomes is not evidence-based and recent international guidelines recommend against this.

Left atrial strain in cardiac surveillance of bone marrow transplant patients with prior anthracycline exposure.

BACKGROUND: Bone marrow transplantation (BMT) has significantly improved survival rates in various hematological malignancies. However, this has led to an increased prevalence of long-term cardiotoxicity, particularly in those with prior anthracycline (AC) therapy. OBJECTIVES: To evaluate changes in left atrial (LA) volume and function, including LA strain, in BMT patients with prior AC exposure and evaluate its utility as a marker of diastolic dysfunction. METHODS: This was a cross-sectional analysis of 79 BMT patients with prior AC exposure who underwent a comprehensive surveillance transthoracic echocardiogram compared to age-matched healthy volunteers. Left ventricular (LV) and LA parameters were evaluated between the 2 groups. BMT patients were stratified using traditional measures of diastolic function and additionally utilizing LA strain. RESULTS: LV systolic dysfunction with reduced LVEF (13/79) or global longitudinal strain (29/79) was present in BMT patients. There were no differences in LA volumes between the two groups. LA reservoir strain (30.1 ± 11.2% vs 34.1 ± 9.6%, p < 0.001) and LA conduit strain (13.6 ± 8.4% vs 17.0 ± 10.5%, p < 0.001) were reduced in the BMT group compared to controls. LA reservoir strain had modest correlation with mitral annular e' velocity (r = 0.468, p < 0.001). Using current diastolic function guidelines, 26/79 BMT patients had evidence of diastolic dysfunction. However, utilizing LA reservoir strain, an additional 35 patients were identified. CONCLUSIONS: LA strain can identify early diastolic dysfunction in BMT patients with prior AC treatment. With diastolic dysfunction known to precede systolic dysfunction post AC, changes in LA reservoir strain may identify more patients with cardiac dysfunction, prompting increased surveillance and treatment.

The utility of strain imaging in the cardiac surveillance of bone marrow transplant patients.

OBJECTIVE: To evaluate the utility of two-dimensional multiplanar speckle tracking strain to assess for cardiotoxicity post allogenic bone marrow transplantation (BMT) for haematological conditions. METHODS: Cross-sectional study of 120 consecutive patients post-BMT (80 pretreated with anthracyclines (BMT+AC), 40 BMT alone) recruited from a late effects haematology clinic, compared with 80 healthy controls, as part of a long-term cardiotoxicity surveillance study (mean duration from BMT to transthoracic echocardiogram 6±6 years). Left ventricular global longitudinal strain (LV GLS), global circumferential strain (LV GCS) and right ventricular free wall strain (RV FWS) were compared with traditionl parameters of function including LV ejection fraction (LVEF) and RV fractional area change. RESULTS: LV GLS (-17.7±3.0% vs -20.2±1.9%), LV GCS (-14.7±3.5% vs -20.4±2.1%) and RV FWS (-22.6±4.7% vs -28.0±3.8%) were all significantly (p=0.001) reduced in BMT+AC versus controls, while only LV GCS (-15.9±3.5% vs -20.4±2.1%) and RV FWS (-23.9±3.5% vs -28.0±3.8%) were significantly (p=0.001) reduced in BMT group versus controls. Even in patients with LVEF >53%, ~75% of patients in both BMT groups demonstrated a reduction in GCS. CONCLUSION: Multiplanar strain identifies a greater number of BMT patients with subclinical LV dysfunction rather than by GLS alone, and should be evaluated as part of post-BMT patient surveillence. Reduction in GCS is possibly due to effects of preconditioning, and is not fully explained by AC exposure.