Maude Pagé

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.

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. HighlightsLA function by STE is altered in FD.ERT improves LA function after 1 year of treatment.Strain parameters are associated with AF and stroke.

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.

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.

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.

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.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 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 (SDs) of the distributions of inter-method difference for the comparison of the new score with RNA was 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.

Severe Asymptomatic Unicuspid Aortic Stenosis, Myocardial Fibrosis, and Sudden Death: Relevance of Multimodality Imaging

Graphical abstract

RIGHT VENTRICULAR ECHOCARDIOGRAPHIC INDICES PREDICT HIGH ALTITUDE PULMONARY PRESSURE INCREMENT IN LOWLANDERS

BACKGROUND: The physiopathology and determinants of high altitude pulmonary edema (HAPE) remain ill defined, but increased hypoxia-related pre-capillary pulmonary artery pressure (PAP) has been shown as a key component. No parameter has been validated to predict the development of HAPE among recreational climbers. We aimed to assess whether baseline right ventricular (RV) echocardiographic indices were predictive of an increased hypoxic PAP response. METHODS: 14healthy lowlander subjects (8men; ages 27-65 years old) were assessed by echocardiography at sea level (Montreal) and at 3450m (Namche Bazaar) and 4730m (Chukkung) during an expedition in the Khumbu Valley, Nepal. Baseline RV performance parameterswere analysed and compared to the systolic PAP maximal increment observed at high altitude; correlation coefficient (r) and coefficient of determination (r2) were calculated. RESULTS: At high altitude, none of the subjects had clinical criteria for HAPE, although all except one had ultrasound signs of interstitial lung water. Systolic PAP increased in all subjects between Montreal and Chukkung (mean PAP 27.4 +/5.4 mmHg vs. 39.3 +/7.7mmHg respectively; p<0.001). Sea level RV Tei index assessed by tissue doppler was moderately correlated to the PAP increment (r21⁄4 0.37), as was the s’ velocity at the tricuspid annulus (r2 1⁄4 0.27). Baseline Tricuspid Annular Plane Systolic Excursion (TAPSE) was strongly correlated to the PAP increment (fig. 1). The tricuspid E/e’ showed no correlation with PAP altitude-induced increment. RV free wall longitudinal strain was assessed and, although baseline value did not correlate with PAP increment (r21⁄4 0.05), strain increment betweenMontreal and Chukkung was moderately correlated to the PAP reached at the highest altitude (r2 1⁄4 0.39). CONCLUSION: RV echocardiographic indices such as TAPSE, s’ and Tei index at sea level correlate to the level at which PAP increases in lowlanders after a sub-acute ascent to high altitude. These findings reinforce the role of RV function in the development of high altitude pulmonary diseases and, should they be confirmed on a larger population, suggest that these indices could help counsel lowlanders before attempting high-altitude climbs. 315 ROUTINE TRANSESOPHAGEAL ECHO PRIOR TO ATRIAL FIBRILLATION/FLUTTER ABLATIONS IN LOW RISK PATIENTS ARE THEY NECESSARY?