Right ventricular global longitudinal strain is an independent predictor of right ventricular function: a multimodality study of cardiac magnetic resonance imaging, real time three-dimensional echocardiography and speckle tracking echocardiography.

OBJECTIVES: Accurate assessment of right ventricular (RV) systolic function is important, as it is an established predictor of mortality in cardiac and respiratory diseases. We aimed to compare speckle tracking-derived longitudinal deformation measurements with traditional two-dimensional (2D) echocardiographic parameters, as well as real time three-dimensional echocardiography (RT3DE) and cardiac magnetic resonance imaging (CMR)-derived RV volumes and ejection fraction (EF). METHOD: Subjects referred for CMR also underwent echocardiography. On both RT3DE and CMR, we measured RV volumes and EF. On 2D echocardiography, we analyzed RV fractional area change, RV internal diastolic diameter, tricuspid annular plane systolic excursion, tricuspid annular tissue Doppler-derived velocity, myocardial performance index, and RV global longitudinal strain (RV GLS). RESULTS: Sixty subjects were recruited (mean age = 45 ± 10 years; 60% male). RV GLS (R = -0.69, P < 0.001) and RT3DE RVEF (R = 0.56, P < 0.001) correlated well with CMR RVEF. RT3DE RV end-diastolic (RVEDV) and end-systolic (RVESV) volumes also correlated with CMR RV volumes: RVEDV, R = 0.74, P < 0.001 and RVESV, R = 0.84, P < 0.001. In addition, RV GLS best predicted the presence of RV dysfunction, defined as RVEF <48% on CMR (hazard ratio = 7.0 [1.5-31.7], P < 0.01). On receiver operator characteristic analysis, a RV GLS of -20% was the most sensitive and specific predictor of RV dysfunction (AUC 0.8 [0.57-1.0], P < 0.02). CONCLUSION: RVEF and volumes estimated on RT3DE were closely correlated with CMR measurements. When compared to more traditional markers of RV systolic function and RT3DE, RVGLS produced the highest correlation with CMR RVEF and was a good predictor of RV dysfunction. RV GLS should be considered a complementary modality to RT3DE and CMR in the assessment of RV systolic function.

Left ventricular torsional dynamics post exercise for LV diastolic function assessment.

AIMS: 2D speckle tracking echocardiography allows for assessment of left ventricular (LV) torsional deformation as a composite function of the radial, longitudinal and circumferential fibres. We test the hypothesis that post-exercise LV torsional dynamics are more sensitive markers for myocardial dysfunction than resting measures, and better predictors for exercise capacity compared to post-exercise LV diastolic filling pressure (E/e'). METHODS: We studied 88 patients referred for stress echocardiogram. Treadmill exercise was performed using Bruce protocol, and echo images were acquired using GE Vivid 7. LV rotational dynamics were analysed by speckle tracking method using the GE ECHOPAC software. Tertiles were defined according to exercise capacity measured by the achieved metabolic equivalents (METS) adjusted for age and gender. Comparison was made between LV torsional dynamics and E/e' to correlate with METS to predict exercise capacity. RESULTS: Mean age of the study population was 58 years, 48% females. Patients with systolic dysfunction or evidence of ischaemia were excluded from the analysis. No significant correlation was found between METS and LV torsion measures at rest. There was statistically significant correlation between METS and post-exercise LV torsion (r=0.34, p=0.001), twist velocity increase (r=0.27, p=0.01), and incremental change in torsion (r=0.22, p<0.05). In addition, a correlation was also shown between post-exercise E/e' and METS (r=-0.33, p=0.002). CONCLUSION: Post-exercise LV torsional dynamics correlate with exercise capacity and may be a useful tool for assessing LV myocardial function in subjects with normal LVEF.

Electrocardiograph changes, troponin levels and cardiac complications after orthopaedic surgery.

INTRODUCTION: The relationship between electrocardiograph (ECG) changes and troponin levels after the emergency orthopaedic surgery are not well characterised. The aim of this study was to determine the correlation between ECG changes (ischaemia or arrhythmia), troponin elevations perioperatively and cardiac complications. MATERIALS AND METHODS: One hundred and eighty-seven orthopaedic patients over 60 years of age were prospectively tested for troponin I and ECGs were performed on the fi rst 3 postoperative mornings or until discharge. RESULTS: The incidences of pre- and postoperative troponin elevation were 15.5% and 37.4% respectively, the majority were asymptomatically detected. Most of the patients who sustained a troponin rise did not have any concomitant ECG changes (51/70 or 72.9%). Postoperative ECG changes were noted in 18.4% (34/185) and of those with ECG changes, slightly more than half (55.9%) had a troponin elevation. Most ECG changes occurred on postoperative day 1 and were non-ST elevation in type. ECG changes occurred more frequently with higher troponin levels. Postoperative troponin elevation (P = 0.018) and not preoperative troponin level (P = 0.060) was associated with ECG changes on univariate analysis. Two premorbid factors were predictors of postoperative ECG changes using multivariate logistical regression; age [odds ratio (OR), 1.05; 95% CI, 1.005 to 1.100, P = 0.029) and sex OR, 2.4; 95% CI, 1.069 to 5.446, P = 0.034). Twenty patients sustained postoperative cardiac complications; 9 (45%) were associated with ECG changes and 16 (80%) with postoperative troponin elevation. Pre- or postoperative troponin elevation better predicted cardiac complications compared with preoperative ECG changes. CONCLUSION: Electrocardiograph changes do not necessarily accompany troponin elevations after the emergency orthopaedic surgery but are more likely to have higher troponin levels. The best predictor of postoperative cardiac complications is troponin elevation.

Does cardiology intervention improve mortality for post-operative troponin elevations after emergency orthopaedic-geriatric surgery? A randomised controlled study.

OBJECTIVES: Troponin elevations are common after emergency orthopaedic surgery and confer a higher mortality at one year. The objective was to determine if comprehensive cardiology care after emergency orthopaedic surgery reduces mortality at one year in patients who sustain a post-operative troponin elevation versus standard care. METHODS: A randomised controlled trial was conducted at a metropolitan teaching hospital in Melbourne, Australia. 187 consecutive patients were eligible with 70 patients randomised. Troponin I was tested peri-operatively and patients with a troponin elevation were randomised to cardiology care versus standard ward management. The main outcome measure was one year mortality. RESULTS: The incidence of a post-operative troponin elevation was 37.4% (70/187) and these 70 patients were randomised. In-hospital cardiac complications were similar between the randomised groups: standard care (7/35 or 20.0%) versus cardiology care (8/35 or 22.9%). There was no difference in 1 year mortality between the randomised groups (6/35 or 17.1% in each group). Multivariate predictors of 1 year mortality were post-operative troponin elevation OR 4.3 (95% CI, 1.1-16.4, p=0.035), age OR 1.1 (95% CI, 1.02-1.2, p=0.016) and number of comorbidities OR 2.1 (95% CI, 1.3-3.5, p=0.004). At 1 year 35/187 (18.7%) sustained a cardiac complication and 23/35 (65.7%) had a troponin elevation. CONCLUSIONS: There was no difference in mortality between patients with a post-operative troponin elevation randomised to cardiology care compared with standard care. Troponin elevation predicted one year mortality. Further research is needed to find an effective intervention to reduce mortality.

Stroke and Takotsubo cardiomyopathy: is there more than just cause and effect?

Takotsubo cardiomyopathy has been described as a consequence of stroke or a cardioembolic source of stroke. We present the case of a 43 year-old woman who suffered from Takotsubo cardiomyopathy and subsequently developed a large left cerebellar infarct without significant neurological deficits nor evidence of a cardioembolic cause. Catecholamine excess has been postulated to cause myocardial stunning in Takotsubo cardiomyopathy and some cases of cerebral ischaemia. In this case, the concurrent occurrence of Takotsubo cardiomyopathy and stroke without an identifiable source suggests that there may be a possible unifying pathogenetic mechanism.