Right ventricular ejection fraction with cardiac magnetic resonance using a wall motion score.

BACKGROUND: The volumetric method in cardiac magnetic resonance (CMR), the reference standard for right ventricular ejection fraction (RVEF), requires expertise because of the complex right ventricular geometry and anatomical landmarks. AIM: The aim of our retrospective study was to describe a new method to evaluate RVEF based on wall motion score index (WMSI) in CMR. METHODS: Visual assessment of wall motion was performed using an eight-segment model (normokinesia=1, hypokinesia=2, akinesia=3). Correlation between WMSI (WMS/8) and the reference volumetric RVEF was analysed. A regression equation was derived to convert the WMSI into RVEF. The accuracy of CMR WMSI-derived RVEF compared with CMR volumetric RVEF was evaluated using Bland-Altman analysis. RESULTS: In the 112 patients using the volumetric method, the mean RVEF was 48±14%. Fifty-nine patients had normal RV kinetics (WMSI=1), which corresponded to a volumetric RVEF of 56% (standard deviation 7%; range 43-76%). CMR WMSI showed a strong correlation with CMR volumetric RVEF (Spearman's Rho=-0.69). A regression equation was created: RVEF=80-22×WMSI. Overall, the WMSI-derived RVEF resulted in good agreement with the CMR volumetric RVEF (mean bias-3%, standard deviation±7.5%). In addition, using a WMSI cut-off of≥1.5 was highly accurate (92%) to predict a reference RVEF of˂45%, an important prognostic indicator in CMR. CONCLUSIONS: Our results suggest that using the WMS in CMR (eight-segment) to estimate RVEF is accurate, and correlates well with the volumetric method. A WMSI≥1.5 is optimal to categorize patients in the higher-risk subset of CMR RVEF˂45%.

Assessment of LVEF using a new 16-segment wall motion score in echocardiography.

BACKGROUND: Simpson biplane method and 3D by transthoracic echocardiography (TTE), radionuclide angiography (RNA) and cardiac magnetic resonance imaging (CMR) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. Wall motion score index (WMSI) by TTE is an accepted complement. However, the conversion from WMSI to LVEF is obtained through a regression equation, which may limit its use. In this retrospective study, we aimed to validate a new method to derive LVEF from the wall motion score in 95 patients. METHODS: The new score consisted of attributing a segmental EF to each LV segment based on the wall motion score and averaging all 16 segmental EF into a global LVEF. This segmental EF score was calculated on TTE in 95 patients, and RNA was used as the reference LVEF method. LVEF using the new segmental EF 15-40-65 score on TTE was compared to the reference methods using linear regression and Bland-Altman analyses. RESULTS: The median LVEF was 45% (interquartile range 32-53%; range from 15 to 65%). Our new segmental EF 15-40-65 score derived on TTE correlated strongly with RNA-LVEF (r = 0.97). Overall, the new score resulted in good agreement of LVEF compared to RNA (mean bias 0.61%). The standard deviations (s.d.s) of the distributions of inter-method difference for the comparison of the new score with RNA were 6.2%, indicating good precision. CONCLUSION: LVEF assessment using segmental EF derived from the wall motion score applied to each of the 16 LV segments has excellent correlation and agreement with a reference method.

Impaired Left Atrial Function in Fabry Disease: A Longitudinal Speckle-Tracking Echocardiography Study.

BACKGROUND: Fabry disease (FD) is characterized by the accumulation of sphingolipids in multiple organs, including the left atrium. It is uncertain if the left atrial (LA) reservoir, conduit, and contractile functions evaluated by speckle-tracking echocardiography are affected in Fabry cardiomyopathy and whether enzyme replacement therapy can improve LA function. METHODS: In this retrospective cohort study, LA strain, strain rates, and phasic LA volumes were studied in 50 patients with FD and compared with values in 50 healthy control subjects. RESULTS: All three LA phasic functions were altered. Peak positive strain (reservoir function) was 38.9 ± 14.9% versus 46.5 ± 10.9% (P = .004), and late diastolic strain (contractile function) was 12.6 ± 5.9% versus 15.6 ± 5.3% (P = .010). In 15 patients who started enzyme replacement therapy during the study, most of the LA parameters improved at 1-year follow-up (peak positive strain from 32.0 ± 13.5% to 38.0 ± 13.5%, P = .006), whereas there was a trend toward deterioration in 15 patients who never received treatment (peak positive strain from 47.3 ± 10.8% to 41.3 ± 9.3%, P = .058). Nine patients with FD (21%) experienced new-onset atrial fibrillation or stroke during 4-year follow-up. By univariate analysis, peak positive strain and early diastolic strain demonstrated significant associations with clinical events, surpassing conventional echocardiographic parameters and clinical characteristics. CONCLUSIONS: LA reservoir, conduit, and contractile functions by speckle-tracking echocardiography were all affected in FD. Enzyme replacement therapy improved LA function. LA strain parameters were associated with atrial fibrillation and stroke.

Metabolically Active Brown Fat Mimicking Pericardial Metastasis on PET/CT: The Discriminating Role of Cardiac Magnetic Resonance Imaging.

Metabolically active mediastinal brown adipose tissue may be mistakenly diagnosed as a malignancy on 18F-fluoro-2-deoxy-D-glucose (FDG)/positron emission tomography (PET). We report the case of a patient with locally recurrent breast carcinoma in which staging PET/CT revealed a suspicious pericardial lesion for which the patient was referred to our centre. The novelty of this case resides in the fact that by tissue characterization, cardiac magnetic resonance imaging allowed the determination that the lesion corresponded to brown fat, a reassuring finding with important impact on management, because the presence of pericardial metastasis would have disqualified this patient for curative resection of her cancer recurrence.

Primary Cardiac Lymphoma: Diagnosis and the Impact of Chemotherapy on Cardiac Structure and Function.

We report a case of primary cardiac lymphoma presenting as myopericarditis and rapidly deteriorating into biventricular heart failure and ventricular arrhythmias. Computed tomography and cardiac magnetic resonance (CMR) imaging showed extensive myocardial infiltration with typical patterns on tissue characterization CMR images, raising clinical suspicion. Diagnosis was confirmed by myocardial histologic examination. Marked regression of tumor burden was apparent after 6 cycles of anthracycline-based chemotherapy. This case illustrates that a high degree of suspicion for this rare entity is mandated to institute timely treatment. Rapid tumor lysis may induce life-threatening acute cardiac decompensation that requires intensive monitoring and support therapy.

Aortopulmonary Fistula after Multiple Pulmonary Artery Stenting and Dilatation for Postarterial Switch Supravalvular Stenosis.

We present a case of iatrogenic aortopulmonary fistula following pulmonary artery (PA) stenting late after arterial switch operation (ASO) for D-transposition of the great arteries (D-TGA), an unusual complication that may be encountered more frequently in contemporary adult cardiology clinics. The diagnosis should be sought in the face of unexplained heart failure in patients who underwent ASO and subsequent PA angioplasty. Treatment should be instituted in a timely fashion, and options include surgical correction or implantation of a duct occluder or covered stent.

Brain Natriuretic Peptide Levels and the Occurrence of Subclinical Pulmonary Edema in Healthy Lowlanders at High Altitude.

BACKGROUND: High altitude (HA) pulmonary edema (PE) results from complex and misunderstood interactions between adaptation mechanisms. We assessed the occurrence of subclinical PE and brain natriuretic peptide (BNP) levels among nonacclimatized individuals during an expedition on Mount Elbrus (5642 m). METHODS: Seven subjects underwent assessment of vital signs, Lake Louise Score, ultrasound lung comets using handheld echography and circulating BNP using capillary testing at different stages of ascension, in addition to baseline echocardiography. Friedman tests were used to compare serial measurements. RESULTS: Heart rate, Lake Louise Score (P < 0.0001) and blood pressure (P = 0.037) increased during ascension; oxygen saturation decreased (P < 0.0001). BNP increased (40.7 ± 16.8 vs 19.7 ± 3.04 pg/mL; P < 0.01) after the summit, as did ultrasound lung comet count throughout ascension (P < 0.0001), but both parameters were not correlated (r = 0.36; P = 0.42). Post-summit peak BNP correlated with baseline left ventricular mass index (r = -0.79; P = 0.033). CONCLUSION: This study confirms the high incidence of subclinical PE during subacute exposure to hypobaric hypoxia and enhancement of this phenomenon after exertion. Although not correlated with the degree of PE, BNP levels increased after sustained effort at HA, but not at rest. Further investigation is needed to determine the mechanisms underlying the BNP response at HA and its usefulness as a monitoring tool during expeditions.

Aortic dilation rates in patients with biscuspid aortic valve: correlations with cusp fusion phenotype.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare the pattern and rate of aortic dilation in patients with isolated non-surgical bicuspid aortic valve (BAV) with left-right fusion (L-R) and right-non coronary fusion (R-N). Although the etiology and optimal management of aortic dilation associated with BAV remain the subject of debate, recent data have suggested that L-R and R-N cusp fusion phenotypes represent distinct pathological entities. METHODS: Consecutive patients with BAV and at least two echocardiographic assessments made between 2006 and 2012 were reviewed. Patients with hemodynamically significant valvular disease, aortic aneurysm (> 50 mm) or unrepaired aortic coarctation were excluded. Longitudinal analyses of the aortic annulus, sinuses of Valsalva, sinotubular junction and ascending aortic diameters were performed using mixed-effect models. RESULTS: A total of 590 echocardiographic studies was analyzed in 212 patients (mean age 33 ± 14 years), of which 147 had L-R phenotype and 65 had R-N phenotype. The median follow up was 3.6 years. Baseline aortic diameters at the sinuses of Valsalva were larger in patients with L-R compared to R-N fusion (33.8 ± 5.3 mm versus 30.8 ± 4.8 mm; p < 0.001). At this level, the rate of aortic dilation was higher with L-R versus R-N fusion (0.41 ± 0.11 mm/year versus 0.01 ± 0.08 mm/year; p < 0.001). The rate of proximal ascending aortic dilation was also higher with L-R versus R-N fusion (0.58 ± 0.08 mm/year versus 0.18 ± 0.09 mm/year; p < 0.001). CONCLUSION: Aortic dilation rates vary according to the pattern of BAV cusp fusion, with faster rates of aortic sinus and ascending aortic dilation associated with the L-R compared to R-N phenotype.

Echocardiographic assessment of cardiac performance in response to high altitude and development of subclinical pulmonary edema in healthy climbers.

BACKGROUND: Data regarding the effect of high altitude on heart function are sparse and conflicting. We aimed to assess the right and left ventricular responses to altitude-induced hypoxia and the occurrence of subclinical pulmonary edema. METHODS: Echocardiography was performed according to protocol on 14 subjects participating in an expedition in Nepal, at 3 altitude levels: Montreal (30 m), Namche Bazaar (3450 m), and Chukkung (4730 m). Systematic lung ultrasound was performed to detect ultrasound lung comets. RESULTS: Pulmonary artery systolic pressure increased in all subjects between Montreal and Chukkung (mean 27.4 ± 5.4 mm Hg vs. 39.3 ± 7.7 mm Hg; P < 0.001). Right ventricular (RV) myocardial performance index (MPI) increased significantly (0.32 ± 0.08 at 30 m vs. 0.41 ± 0.10 at 4730 m; P = 0.046). A trend toward deteriorated RV free wall longitudinal strain was observed between Montreal and Chukkung (-25.9 [5.3%] vs. -21.9 [6.4%]; P = 0.092). The left ventricular early diastolic inflow velocity/atrial mitral inflow velocity and early diastolic inflow velocity/mean of the maximal early diastolic mitral annulus tissue doppler velocities ratios remained unchanged. At 4730 m, ultrasound lung comets were seen in all subjects except 1. None had clinical criteria for high-altitude pulmonary edema (HAPE). All altered parameters normalized after return to sea level. CONCLUSION: Subclinical HAPE is frequent in healthy lowlander climbers. This is the first study to document a trend towards decreased RV free wall strain and MPI increment at high altitude. Whether rising RV MPI is a physiologic adaptive mechanism to hypoxia or a pathologic response identifying HAPE-susceptible subjects needs further study.

Temporal trends in revascularization and outcomes after acute myocardial infarction among the very elderly.

BACKGROUND: Few data are available on time-related changes in use and outcomes of invasive procedures after acute myocardial infarction in very elderly patients. Our objective was to describe trends in revascularization procedures and outcomes in a provincial cohort of very elderly patients who had experienced acute myocardial infarction. METHODS: We used a database of hospital discharge summaries to identify all patients aged 80 years or older admitted for acute myocardial infarction in Quebec. We used the provincial database of physicians' services and medication claims to assess treatment and obtain data on survival. RESULTS: Between March 1996 and March 2007, 29 750 patients aged 80 years or older were admitted to hospital for acute myocardial infarction. During this period, use of percutaneous coronary interventions increased from 2.2% to 24.9%, and use of coronary artery bypass graft surgery increased from 0.8% to 3.1%. Evidence-based prescriptions of medication increased over time (p < 0.001). The prevalence of reported comorbidities was higher during the period of 2003-2006 than during the 1996-1999 period. One-year mortality improved over time (46.5% for 1996-1999 v. 40.9% for 2003-2006, p < 0.001) but remained unchanged in the subgroup of patients who did not undergo revascularization. INTERPRETATION: The use of revascularization, especially percutaneous coronary interventions, in the very elderly after acute myocardial infarction has been growing at a rapid pace, while the prevalence of reported comorbidities has been increasing in this population. Revascularization procedures are no longer restricted to younger patients. In the context of an aging population, it is imperative to determine whether these changes in practice are cost-effective.