Citations

The non‐invasive evaluation of prosthetic valve function is challenging. The effects of flow rate, valvular geometry, leaflet motion, and pressure recovery all impact the Doppler assessment of prosthetic performance. Differentiating prosthesis obstruction from pressure recovery in patients who are found to have high Doppler velocities across an aortic valve prosthesis is critical in order to direct appropriate management. In this manuscript, we present two cases of patients with aortic valve prosthesis with high Doppler velocities and review the pathophysiology and evaluation of prosthesis function. © 2014 Wiley Periodicals, Inc.

Background— Among patients with severe aortic stenosis (AS) and preserved ejection fraction, those with low gradient (LG) and reduced stroke volume may have an adverse prognosis. We investigated the prognostic impact of stroke volume using the recently proposed flow-gradient classification. Methods and Results— We examined 1704 consecutive patients with severe AS (aortic valve area <1.0 cm 2 ) and preserved ejection fraction (≥50%) using 2-dimensional and Doppler echocardiography. Patients were stratified by stroke volume index (<35 mL/m 2 [low flow, LF] versus ≥35 mL/m 2 [normal flow, NF]) and aortic gradient (<40 mm Hg [LG] versus ≥40 mm Hg [high gradient, HG]) into 4 groups: NF/HG, NF/LG, LF/HG, and LF/LG. NF/LG (n=352, 21%), was associated with favorable survival with medical management (2-year estimate, 82% versus 67% in NF/HG; P <0.0001). LF/LG severe AS (n=53, 3%) was characterized by lower ejection fraction, more prevalent atrial fibrillation and heart failure, reduced arterial compliance, and reduced survival (2-year estimate, 60% versus 82% in NF/HG; P <0.001). In multivariable analysis, the LF/LG pattern was the strongest predictor of mortality (hazard ratio, 3.26; 95% confidence interval, 1.71–6.22; P <0.001 versus NF/LG). Aortic valve replacement was associated with a 69% mortality reduction (hazard ratio, 0.31; 95% confidence interval, 0.25–0.39; P <0.0001) in LF/LG and NF/HG, with no survival benefit associated with aortic valve replacement in NF/LG and LF/HG. Conclusions— NF/LG severe AS with preserved ejection fraction exhibits favorable survival with medical management, and the impact of aortic valve replacement on survival was neutral. LF/LG severe AS is characterized by a high prevalence of atrial fibrillation, heart failure, and reduced survival, and aortic valve replacement was associated with improved survival. These findings have implications for the evaluation and subsequent management of AS severity.

Objective Bicuspid aortic valve (BAV) is associated with a higher risk of type A aortic dissection (AD) compared with tricuspid aortic valve (TAV). We sought to study differences between patients with BAV and TAV with AD. Design and setting Observational descriptive analysis of clinical, imaging and pathological characteristics of all patients with confirmed BAV and AD from 1980–2010, compared with a consecutive TAV group with AD. Results Of 47 patients with BAV (mean age 58±14, 77% male), 31 (66%) had acute AD, 16 (34%) had chronic AD, 40 (85%) had typical BAV, 32 (68%) had hypertension and 11 (23%) had previous aortic coarctation repair. Of 53 patients with TAV (mean age 66±13 (p=0.007), 76% male), 34 (66%) had acute AD (p=1.0) and 46 (87%) had hypertension (p=0.03). More patients with BAV had known aortic dilatation prior to AD (49% versus 17%, p=0.001). Presentation symptoms were identical between groups (p=NS). Maximal ascending aortic diameter at AD was higher in patients with BAV (66±15 mm vs 56±11 mm, p=0.0004). Previous aortic valve replacement (AVR) was more common in BAV (23% vs 6%, p=0.02). Of 11 patients with BAV with previous isolated AVR, 7 had ≥moderate ascending aorta dilatation at the time of surgery. Patients with BAV had increased aortic jet velocity (28% vs 10%) and more severe aortic stenosis (19% vs 0%) at presentation (p=0.04 and 0.002, respectively). In acute AD, aortic medial degeneration affected 75% of BAV specimens and 41% TAV specimens (p=0.01) while aortic atherosclerosis was more frequent in TAV (56% vs 26%, p=0.02). Conclusions Compared with patients with TAV, patients with BAV with type A AD are younger, have less hypertension, more valve stenosis and previous AVR, higher maximal aortic dimension, worse aortic medial degeneration, high prevalence of aortic coarctation, and 1 out of 2 have known aortic dilatation prior to AD. Implementation of current guidelines could have theoretically prevented AD in several patients with BAV.

Background— Low-gradient severe aortic stenosis with preserved ejection fraction is an increasingly recognized entity, and symptomatic patients may benefit from aortic valve replacement. However, systemic hypertension frequently coexists with low-gradient severe aortic stenosis, which itself may cause elevated left ventricular (LV) filling pressures with resultant symptoms of dyspnea. Methods and Results— Symptomatic patients with hypertension (aortic systolic pressure >140 mm Hg) and low-gradient (mean gradient <40 mm Hg) severe aortic stenosis (aortic valve area <1 cm 2 ) with preserved ejection fraction (ejection fraction >50%) who underwent invasive hemodynamic catheterization of the left and right sides of the heart received infusion of intravenous sodium nitroprusside to reduce blood pressure and arterial afterload. At baseline, patients had severe hypertension (aortic systolic pressure, 176±26 mm Hg), pulmonary hypertension (mean pressure, 39±12 mm Hg), elevated LV end-diastolic pressure (19±5 mm Hg), and reduced stroke volume (33±8 mL/m 2 ). All measures of afterload were reduced with nitroprusside ( P <0.001 for all). Nitroprusside reduced mean pulmonary artery pressure (25±10 mm Hg) and LV end-diastolic pressure (11±5 mm Hg; P <0.001 for both compared with baseline). Aortic valve area (0.86±0.11 to 1.02±0.16 cm 2 ; P =0.001) and mean gradient (27±5 to 29±6 mm Hg; P =0.02) increased with nitroprusside. Conclusions— Systemic hypertension in low-gradient severe aortic stenosis with preserved ejection fraction is associated with elevated LV filling pressures and pulmonary hypertension. Treatment of hypertension with vasodilator therapy results in a lowering of the total LV afterload, with a decrease in LV filling pressures and pulmonary artery pressures. These findings have important implications for the management of patients with low-gradient severe aortic stenosis with preserved ejection fraction and hypertension.

Retroperitoneal fibrosis is a rare condition characterized by the presence of inflammatory and fibrous retroperitoneal tissue that surrounds and often encases abdominal structures. In this report we describe an unusual presentation of retroperitoneal fibrosis and inferior vena cava (IVC) obstruction that was unidentified by noninvasive testing and ultimately diagnosed using exercise right heart catheterization and venography. Exercise hemodynamic catheterization revealed a high pressure gradient across the IVC obstruction during exercise that resulted in reduced preload and inappropriately low cardiac output reserve. The patient ultimately underwent angioplasty and stenting of the obstruction resulting in resolution of his symptoms. © 2013 Wiley Periodicals, Inc.

Background— The pathophysiology of low flow, low gradient severe aortic stenosis (LGSAS) with preserved ejection fraction is poorly understood. It has been proposed that abnormalities of arterial circulation are a major contributor to this syndrome. Methods and Results— We invasively examined systemic arterial afterload (effective arterial elastance, Ea; total arterial compliance, Ca; and systemic vascular resistance index) in patients with LGSAS (mean gradient, <40 mm Hg; aortic valve area, <1.0 cm 2 ) and preserved ejection fraction (≥50%), and compared these findings with patients with high gradient (≥40 mm Hg) severe aortic stenosis (HGSAS) and moderate AS (mean gradient, <40 mm Hg; aortic valve area, >1.0 cm 2 ). Patients with LGSAS (n=36), HGSAS (n=31), and moderate AS (n=19) were similar with respect to age, sex, body size, symptoms, comorbidities, and ejection fraction. Aortic valve area was similar between groups with LGSAS and HGSAS, but the patients with LGSAS had reduced stroke volume index and cardiac index ( P =0.003 for both). In comparison with patients with HGSAS and moderate AS, measures of afterload, including Ea (4.02±0.98 versus 3.13±0.81 and 3.06±0.79 mm Hg·m 2 /mL; P <0.0001) and systemic vascular resistance index (3116±799 versus 2515±645 and 2380±546 dyn·s·m 2 /cm 5 ; P =0.001), were significantly higher in LGSAS, whereas Ca was lower (0.46±0.16 versus 0.57±0.13 and 0.59±0.19 mL/m 2 per mm Hg; P =0.002). All invasive measures of arterial afterload were related to stroke volume index. Conclusions— Patients with LGSAS and preserved ejection fraction display elevated arterial afterload compared with patients with HGSAS and moderate AS. These findings identify systemic arterial effects that contribute to the hemodynamic presentation in patients with LGSAS and help to further define this entity.

A 60-year-old man with a dual-chamber implantable cardioverter defibrillator and severe dyspnea on exertion due to apical hypertrophic cardiomyopathy underwent a septal myectomy and radiofrequency maze procedure. Following the procedure a persistent delay in atrial sensing was observed and was most likely a result of iatrogenic conduction delay from right atrial ablation lines. These observations suggest that atrial conduction properties can be altered during the surgical maze procedure and should be considered in the differential diagnosis of sensing or pacing malfunction.

Objectives. To determine the importance of acute cardiac events as a cause of mortality compared to non-cardiac events in the four month period following liver transplantation (LT) using current preoperative cardiac screening strategies.Patients and Methods. We retrospectively reviewed timing, type, and outcome of adverse cardiac events, and all cause mortality in the 4 month postoperative period in 393 consecutive LT patients from October 1999 to February 2008.Results. Of 30 total deaths (7.6% overall mortality rate), 27 (90%) were due to surgical or medical complications and 3 (10%) were primary cardiac deaths (0.8% cardiac mortality rate). Acute cardiac events occurred in 26 patients (6.6%), including 13 arrhythmias (50%), 7 new onset heart failures (27%), and 6 myocardial infarctions (23%). Twelve of 13 intraoperative events were arrhythmias (92%) including two of three cardiac deaths.Conclusions. Using current preoperative screening recommendations, deaths from primary cardiac events within four months of LT are very uncommon (0.8%), especially compared with deaths related to medical and surgical complications (6.9%).