Michael J.A. Williams

Biopsy-induced flail tricuspid leaflet and tricuspid regurgitation following orthotopic cardiac transplantation

Damage to the tricuspid valve apparatus has been described after endomyocardial biopsy and may be associated with hemodynamically significant tricuspid regurgitation (TR). This study was performed to determine the prevalence of TR and flail tricuspid leaflet in cardiac transplant recipients and to evaluate the use of a 45 cm sheath placed directly in the right ventricle during endomyocardial biopsy to reduce the incidence of these complications. Echocardiograms and right heart catheterization data of 72 orthotopic cardiac transplant recipients were assessed for the presence of flail tricuspid leaflet, TR, and right-sided cardiac dysfunction 29 +/- 20 months (mean +/- SD) after transplantation. Moderate or severe TR was present in 23 patients (32%). Ten patients (14%) had flail tricuspid leaflet, with 7 of these having severe TR. Right atrial pressure (10 +/- 5 vs 6 +/- 5 mm Hg, p < 0.05) was higher, cardiac index (2.0 +/- 0.2 vs 2.5 +/- 0.7 L/min/m2, p < 0.05) was lower, and right-sided cardiac dimensions were greater in patients with flail leaflets than in those without flail leaflets. Both the prevalence of flail tricuspid leaflet (41% to 6%, p < 0.0001) and mean grade of TR (2 to 1, p < 0.0001) were reduced after the use of a 45 cm sheath. We conclude that TR secondary to biopsy-induced damage to the valve apparatus occurs in cardiac transplant recipients and is associated with signs of early right-sided heart failure. Use of a 45 cm sheath during endomyocardial biopsy reduces the prevalence of flail tricuspid leaflet and the severity of TR.

Improvement of transthoracic pulmonary venous flow Doppler signal with intravenous injection of sonicated albumin

OBJECTIVES This study was performed to determine whether intravenous injection of a sonicated albumin echocardiographic contrast agent (Albunex) improved the quality of the transthoracic pulmonary venous flow Doppler signal. BACKGROUND Previous studies have shown that transesophageal echocardiography provides pulmonary venous flow Doppler signals superior in quality to those seen with transthoracic echocardiography, which are of limited quality in up to 25% of patients. METHODS Twenty-one patients underwent transthoracic pulsed wave Doppler examination of pulmonary venous flow before, during and after two doses of Albunex ranging from 0.08 ml/kg (low dose) to 0.22 ml/kg (high dose). In addition, five patients underwent transesophageal examination of pulmonary venous flow before and after a 0.08-ml/kg dose of Albunex. The efficacy of the contrast injection was determined using a score that graded the quality of the three components of the pulmonary venous Doppler signal from 0 to 3 (0 = no visible signal; 3 = optimal signal). RESULTS Albunex enhanced the quality of the pulmonary venous Doppler signal from baseline (score 3.9 +/- 1.8 [mean +/- SD]) and at both low (score 5.1 +/- 2.2, p < 0.05) and high doses (score 5.6 +/- 2, p < 0.001). Transthoracic pulmonary venous flow velocities were increased, and peak flow velocity ratios were unchanged, after injection of contrast agent. The contrast-enhanced variables showed good agreement with transesophageal flow velocities. CONCLUSIONS Albunex improves the quality of the transthoracic pulmonary venous Doppler signal, thus allowing improved accuracy of measurement. This approach appears to be effective for increasing the quality of data obtained from the transthoracic examination.

Prevalence and timing of regional myocardial dysfunction after rotational coronary atherectomy

OBJECTIVES This study aimed to evaluate the prevalence and time course of wall motion abnormalities associated with rotational coronary atherectomy. BACKGROUND Although initial clinical studies found evidence of transient wall motion abnormalities after rotational coronary atherectomy, the prevalence and duration of these wall motion abnormalities are unknown. METHODS Using simultaneous echocardiography, we prospectively evaluated 22 patients undergoing rotational atherectomy and compared their wall motion abnormalities with those of 10 patients undergoing coronary angioplasty alone. The extent of wall motion abnormality was quantified and plotted against time to produce curves of abnormal wall motion development and recovery for the two groups. RESULTS The cumulative ischemic time was similar for the two groups ([mean +/- SD] 10.3 +/- 6 min for rotational atherectomy vs. 9.6 +/- 4.2 min for coronary angioplasty, p = 0.73). The rate of return to baseline function was significantly lower in the rotational atherectomy group than in the coronary angioplasty group (rotational atherectomy rate constant 0.069 +/- 0.079/min vs. coronary angioplasty rate constant 1.250 +/- 0.47/min, p = 0.0001). The mean time to recovery of baseline wall motion in the rotational atherectomy group (153 min, 95% confidence interval [CI] 6.5 to 3,600) was significantly longer than in the coronary angioplasty group (2.6 min, 95% CI 1.3 to 5.5, p = 0.0001). Rotational atherectomy burr time was longer in the patients who developed myocardial infarction than in those without myocardial infarction (4.7 +/- 2.4 vs. 3 +/- 1.4 min, p = 0.045). CONCLUSIONS Transient wall motion abnormalities are common after rotational coronary atherectomy and have a longer duration than those observed after coronary angioplasty. This disparity may be a consequence of differences in the mechanisms by which rotational coronary atherectomy and coronary angioplasty produce their effect.

Tricuspid Regurgitation and Right Heart Dimensions at Early and Late Follow-Up After Orthotopic Cardiac Transplantation.

Tricuspid regurgitation is common immediately after cardiac transplantation, but its course over long‐term follow‐up is not known. This study was performed to determine the prevalence of valvular regurgitation and to evaluate if pulmonary hypertension or right ventricular enlargement were associated with the severity of tricuspid regurgitation at early and late follow‐up after cardiac transplantation. Fifty‐five patients had hemodynamic and echocardiographic studies performed at 1 week and 2.4 ± 1.3 years after cardiac transplantation. Right ventricular dimensions were measured and related to the severity of tricuspid regurgitation as assessed by Doppler color flow. There was a fall in right heart filling pressures with decreases in the systolic pulmonary artery pressure (31 mmHg ± 7 mmHg vs 27 mmHg ± 7 mmHg, P = 0.0001) and right atrial pressure (8 ± 5 mmHg vs 6 ± 4 mmHg, P < 0.01). Sixty‐three percent of patients had mild or higher grade tricuspid regurgitation initially and 71% at follow‐up (P = NS). The major determinant of tricuspid regurgitation severity at late follow‐up was the presence of flail tricuspid leaflets (P < 0.0001). There was an association between the change in grade of tricuspid regurgitation and the change in right ventricular diastolic area (P = 0.002) and the change in tricuspid annulus diameter (P < 0.0001). The prevalence of tricuspid regurgitation remains high at late follow‐up after cardiac transplantation and neither pulmonary hypertension nor right ventricular dilatation are prerequisites for tricuspid regurgitation, which can persist in their absence. Flail tricuspid leaflets are the most important predictors of the severity of tricuspid regurgitation following cardiac transplantation.

743-1 Quantitative Transthoracic Three-dimensional Voxel Imaging of the Left Ventricle: Clinical Validation

Recent computational advances have permitted 3-dimensional (3D) reconstruction of echo intensities over the cardiac volume from rotated 2D echo views gated to ECG and respiration. Unlike approaches using selected 2D views, such automated voxel acquisitions conveniently provide rapid spatial appreciation in animated views from multiple perspectives. However, only limited data are available regarding the accuracy of such reconstructions in patients, particularly using the transthoracic approach without the need for TEE. We therefore reconstructed the left ventricles of 10 consecutive patients referred for cardiac gated blood pool scan (GBPS) by transthoracic apical rotation, 5 with abnormal wall motion. LV volume was calculated by summing endocardial areas in parallel cross-sections derived from the voxel data, and compared to GBPS values by validated techniques to normalize counts for attenuation and countstvolume of blood sample. Results Reconstructed volumes (vol) agreed well with those from GBPS: y = r SEE Mean Error End-diastolic vol 0.85x + 17.2 098 8.66 cc 1.4% End-systolic vol 0.89x + 9.42 099 5.29 cc 4.6% Stroke vol 0.93x + 0.64 095 6.01 cc 2.4% Ejection fraction 0.94x - 0.23 0.99 2.59% 5.5% Conclusion 3D volumetric reconstruction of the LV not only provides convenient gated acquisition and ready spatial appreciation from multiple perspectives, but is also quantitatively accurate for LV size and function in patients by the transthoracic approach. This study supports the use of this technique to address clinical and research questions.