Analysis of bi-atrial function using CMR feature tracking and long-axis shortening approaches in patients with diastolic dysfunction and atrial fibrillation.

OBJECTIVES: Atrial function can be assessed using advancing cardiovascular magnetic resonance (CMR) post-processing methods: atrial feature tracking (FT) strain analysis or a long-axis shortening (LAS) technique. This study aimed to first compare the two FT and LAS techniques in healthy individuals and cardiovascular patients and then investigated how left (LA) and right atrial (RA) measurements are related to the severity of diastolic dysfunction or atrial fibrillation. METHODS: Sixty healthy controls and 90 cardiovascular disease patients with coronary artery disease, heart failure, or atrial fibrillation, underwent CMR. LA and RA were analyzed for standard volumetry as well as for myocardial deformation using FT and LAS for the different functional phases (reservoir, conduit, booster). Additionally, ventricular shortening and valve excursion measurements were assessed with the LAS module. RESULTS: The measurements for each of the LA and RA phases were correlated (p < 0.05) between the two approaches, with the highest correlation coefficients occurring in the reservoir phase (LA: r = 0.83, p < 0.01, RA: r = 0.66, p < 0.01). Both methods demonstrated reduced LA (FT: 26 ± 13% vs 48 ± 12%, LAS: 25 ± 11% vs 42 ± 8%, p < 0.01) and RA reservoir function (FT: 28 ± 15% vs 42 ± 15%, LAS: 27 ± 12% vs 42 ± 10%, p < 0.01) in patients compared to controls. Atrial LAS and FT decreased with diastolic dysfunction and atrial fibrillation. This mirrored ventricular dysfunction measurements. CONCLUSION: Similar results were generated for bi-atrial function measurements between two CMR post-processing approaches of FT and LAS. Moreover, these methods allowed for the assessment of incremental deterioration of LA and RA function with increasing left ventricular diastolic dysfunction and atrial fibrillation. A CMR-based analysis of bi-atrial strain or shortening discriminates patients with early-stage diastolic dysfunction prior to the presence of compromised atrial and ventricular ejection fractions that occur with late-stage diastolic dysfunction and atrial fibrillation. KEY POINTS: • Assessing right and left atrial function with CMR feature tracking or long-axis shortening techniques yields similar measurements and could potentially be used interchangeably based on the software capabilities of individual sites. • Atrial deformation and/or long-axis shortening allow for early detection of subtle atrial myopathy in diastolic dysfunction, even when atrial enlargement is not yet apparent. • Using a CMR-based analysis to understand the individual atrial-ventricular interaction in addition to tissue characteristics allows for a comprehensive interrogation of all four heart chambers. In patients, this could add clinically meaningful information and potentially allow for optimal therapies to be chosen to better target the dysfunction.

Passive Leg Raise Stress Echocardiography in Severe Paradoxical Low-Flow, Low-Gradient Aortic Stenosis.

BACKGROUND: Dobutamine stress echocardiography is used to increase transvalvular flow in patients with low-flow, low-gradient aortic stenosis (AS). Dobutamine fails to increase the stroke volume index (SVI) in one third of patients. The aim of this study was to test whether passive leg raise (PLR) added to dobutamine could increase SVI and transvalvular flow in patients with severe paradoxical low-flow, low-gradient AS. METHODS: Forty-five patients with apparent severe low-flow, low-gradient AS on the basis of traditional measurements were included. Twenty-five were categorized as belonging to the paradox group (left ventricular ejection fraction [EF] ≥ 50%) and 20 to the low EF group (left ventricular EF < 50% or "classical" low-flow, low-gradient AS) for comparison. A four-step stress echocardiographic examination was performed: resting conditions (rest), PLR alone (PLR), maximal dobutamine infusion rate (Dmax), and a combination of Dmax and PLR (Dmax+PLR). Aortic valve area, SVI, and mean transvalvular flow were calculated using both the velocity-time integral (VTI) of left ventricular outflow tract and the Simpson method. Changes compared with rest and between the stress maneuvers were analyzed. RESULTS: In the paradox group, compared with rest, left ventricular end-diastolic volume was significantly decreased with Dmax but was completely restored with Dmax+PLR (rest vs Dmax vs Dmax+PLR: 61 ± 15 vs 49 ± 18 mL [P < .001] vs 61 ± 18 mL [P = NS]). The smallest increase in SVI in the paradox group was observed during Dmax (PLR vs Dmax vs Dmax+PLR: VTI, 38 ± 4 mL/m2 [P < .001] vs 36 ± 7 mL/m2 [P = .019] vs 41 ± 7 mL/m2 [P < .001]; Simpson, 28 ± 6 mL/m2 [P < .001], 21 ± 7 mL/m2 [P = NS], 27 ± 7 mL/m2 [P = NS]). Compared with Dmax, Dmax+PLR was able to achieve a higher SVI (VTI, 36 ± 7 vs 41 ± 7 mL/m2 [P < .001]; Simpson, 21 ± 7 vs 27 ± 7 mL/m2 [P < .001]) and transvalvular flow with the Simpson method only (179 ± 56 vs 219 ± 56 mL/sec, P < .001), as well as a higher mean gradient (34 ± 10 vs 39 ± 12 mm Hg, P = .003) and AVA with the Simpson method (0.64 ± 0.21 vs 0.73 ± 0.21 cm2, P = .026). In the low EF group, only SVI VTI (31 ± 8 vs 35 ± 7 mL/m2, P = .034) and mean gradient (29 ± 12 vs 34 ± 14 mm Hg, P = .003) were higher with Dmax+PLR. The proportion of patients with SVI VTI ≥ 35 mL/m2 and increases of SVI VTI of >20% compared with rest was highest with Dmax+PLR in both groups. CONCLUSIONS: Dobutamine decreases preload in paradoxical low-flow, low-gradient AS. Adding PLR counteracts this effect, resulting in increased SVI and flow (in one method). The combined stress maneuver allowed reclassification of some patients from severe to moderate AS and may therefore be useful in selected cases in this population in which severity is uncertain.

Reproducibility of 4D cardiac computed tomography feature tracking myocardial strain and comparison against speckle-tracking echocardiography in patients with severe aortic stenosis.

BACKGROUND: Myocardial strain is an established parameter for the assessment of cardiac function and routinely derived from speckle tracking echocardiography (STE). Novel post-processing tools allow deformation imaging also by 4D cardiac computed tomography angiography (CCT). This retrospective study aims to analyze the reproducibility of CCT strain and compare it to that of STE. METHODS: Left (LV) and right ventricular (RV), and left atrial (LA) ejection fraction (EF), dimensions, global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) were determined by STE and CCT feature tracking in consecutive patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation. RESULTS: 106 patients (mean age 79.9 â€‹± â€‹7.8, 44.3% females) underwent CCT at a median of 3 days (IQR 0-28 days) after STE. In CCT, strain measures showed good to excellent reproducibility (intra- and inter-reader intraclass correlation coefficient ≥0.75) consistently in the LV, RV and LA. In STE, only LV GLS and LA GLS yielded good reproducibility, whereas LV GCS and LV GRS showed moderate, and RV GLS and free wall longitudinal strain (FWLS) poor reproducibility. Agreement between CCT and STE was strong for LV GLS only, while other strain features displayed moderate (LV GCS, LA GLS) or weak (LV GRS, RV GLS and FWLS) inter-modality correlation. CONCLUSION: LV, RV and LA CCT strain assessments were highly reproducible. While a strong agreement to STE was found for LV GLS, inter-modality correlation was moderate or weak for LV GCS, LV GRS, and RV and LA longitudinal strain, possibly related to poor reproducibility of STE measurements.

Evaluation of a protocol for same-day discharge after radial lounge monitoring in a southern Swiss referral percutaneous coronary intervention centre.

AIMS: The aim of the study was to retrospectively evaluate safety and patient satisfaction of same-day discharge after elective radial coronary angiography/percutaneous coronary intervention (PCI) after the implementation of a radial lounge facility. METHODS: All patients admitted to our radial lounge with a planned same-day discharge after an uncomplicated coronary angiography/PCI, having a co-living caregiver, were day enrolled in the study. Rates of same-day discharge, unplanned overnight stay, and in-hospital and first complications [death, myocardial infarction (MI), unplanned coronary angiography, access site hematoma, bleedings requiring hospitalization] were analysed; satisfaction was also evaluated through a questionnaire. RESULTS: From February 2015 to January 2016, 312 patients with a mean age of 66.6 ±â€Š10.8 years were admitted to the radial lounge (coronary angiography, n = 232; PCIs, n = 80). Of them, 245 (78.5%) were discharged the same day. Mean radial lounge monitoring was 6:35 h (interquartile range 5:30-7:30 h). No episodes of death/MI/unplanned coronary angiography were observed both in same-day discharged and postponed patients. Reasons to postpone discharge were: PCI deemed to need prolonged monitoring in 31, patient's preference in 14, femoral shift in 13, surgery in four, chest pain in four, and bleeding in one. At day 1, 11 access site hematoma and one hospitalization for access site bleeding were reported. Patients reported complete satisfaction in 97% of cases. Unplanned overnight stay was common among PCIs patients (RR 6.2, 95% CI 3.9-9.9, P < 0.001). CONCLUSION: A low rate of minor complications was observed in elective radial coronary angiography and PCIs showing the feasibility and safety of the development of an institutional protocol for same-day discharge after the implementation of a radial lounge facility.

The Unique MediGuide Technology For CRT Lead Placement And Catheter Ablation.

Electrophysiologic procedures such as catheter ablation and/or cardiac resynchronization therapy (CRT) are usually performed under fluoroscopic guidance alone. Currently, we are witnessing the birth of a new era in which many patients can be safely and effectively treated without the use of fluoroscopy. Using MediGuide technology continuous fluoroscopy is no longer required to ascertain the position of the device/catheter, which minimizes the radiation exposure for both the physician and patient, with a further benefit by minimal need for contrast agent. This novel system provides real time tracking of devices projected into live fluoroscopy or pre-recorded cine-angiography. MediGuide technology is an important step forward facilitating complex ablation procedures such as AF ablation and CRT implantation.