Preservation of Cardiopulmonary Function in Patients Treated with Ultrasound-Accelerated Thrombolysis in the Setting of Submassive Pulmonary Embolism.

PURPOSE: To evaluate the clinical effectiveness of ultrasound-assisted thrombolysis (USAT) in resolution of right ventricular dysfunction (RVD), preservation of cardiopulmonary function, and quality of life (QoL) in patients with acute submassive pulmonary embolism (PE). MATERIALS AND METHODS: A single-center prospective study of patients presenting with acute PE and signs of RVD, as determined by right ventricle-to-left ventricle diameter ratio (RV:LV) > 0.9 on computed tomographic angiography of the thorax, was performed. Patients underwent USAT with recombinant tissue plasminogen activator. Primary endpoints measured were RV:LV by echocardiogram at baseline presentation and at 72 hours and 90 days after treatment. Secondary endpoints were QoL scores assessed by SF-36 Health Surveys at baseline and at 90 days, cardiopulmonary exercise test (CPET) parameters at 90 days, and procedural outcomes, including response of pulmonary artery pressure (PAP) and procedural complications. RESULTS: Twenty-five patients were treated between June 17, 2013, and September 15, 2014, with mean reduction of RV:LV by echocardiogram from 1.38 ± 0.28 at presentation to 0.92 ± 0.14 (P < .0001) at 72 hours and 0.84 ± 0.25 (P < .0001) at 90 days. SF-36 Health Survey scores demonstrated no long-term self-perceived adverse physical or mental effects as a result of PE. CPET parameters, including VO2max, weight-adjusted VO2, VE/VCO2, and VD/VT demonstrated no pulmonary vascular impairment at 90 days. PAP significantly improved after USAT, with mean initial systolic pressure of 50.46 ± 13.98 mmHg reduced to 39.64 ± 8.66 mmHg (P = .0001). There were no deaths, recurrent venous thromboembolism, hemodynamic decompensation, or hemorrhage. CONCLUSIONS: USAT resulted in significant reduction of RV:LV at 72 hours, which was preserved at 90 days. QoL and objective measures of cardiopulmonary function are preserved at 90 days in this population. Further studies with long-term follow-up are needed to determine the potential value of USAT for the prevention of post-PE syndrome in patients with submassive PE.

Right ventricular free wall stress after tricuspid valve annuloplasty in acute ovine right heart failure.

BACKGROUND: Tricuspid annuloplasty rings may have a direct impact on right ventricular shape and free wall stress, potentially affecting chamber remodeling and recurrent regurgitation. In an acute model of ovine right heart failure, we investigated right ventricular free wall stress after annuloplasty with different prostheses. METHODS: Thirty-xix sheep underwent implantation of sonomicrometry crystals on the tricuspid annulus and right ventricle. Each group consisted of 9 animals that received a flexible (28 ± 1 mm), rigid (29 ± 1 mm), or flexible-rigid hybrid (28 ± 1 mm) ring. Nine control animals had no ring implanted. Hemodynamic, sonomicrometry, and echocardiographic data were collected before (baseline-control group) and during acute right heart failure (control and ring groups). Free wall stress was calculated using the modified Laplace formula for thick shells. Ventricular geometry was determined from 3-dimensional crystal coordinates. RESULTS: Acute right heart failure reduced right ventricular deformation and fractional volume change while increasing pressure, tricuspid regurgitation grade, cross-sectional area, and free wall stress in control animals versus baseline. All rings significantly decreased right ventricular free wall stress versus control except rigid ring at end-systole. There was no significant difference in free wall stress or tricuspid regurgitation between any ring group during acute heart failure and baseline-control group. No significant difference in free wall stress was observed between any of the ring groups. CONCLUSIONS: Acute right heart failure significantly increased right ventricular free wall stress, which was normalized with equal efficacy by all studied prostheses. Chronic studies are needed to evaluate long-term effects of annuloplasty rings on right ventricle free wall stress and remodeling.

Feasibility of transthoracic echocardiographic imaging in non-sedated ovine subjects using a commercial restraint device.

Transthoracic echocardiography (TTE) is a valuable non-invasive imaging research technique. In ovine models of cardiac disease, restraint for TTE often involves sedation even with currently available restraint equipment; our goal was to determine the feasibility of using a commercial restraint device, commonly known as the sheep chair, in minimizing animal stress and the need for sedation while achieving a complete TTE examination. A total of 10 healthy adult Dorset sheep were restrained in a sheep chair for TTE and observed for signs of stress. No animals displayed overt evidence of stress and none required sedation. While individual anatomic variation existed, image quality was sufficient to determine cardiac function. These observations suggest that a sheep chair is a useful aid in minimizing the need for sedation to acquire a full TTE study in ovine subjects.