How much alcohol should we infuse in the coronary artery of hypertrophic cardiomyopathy patients?

BACKGROUND: Although alcohol septal ablation (ASA) is increasingly used in hypertrophic cardiomyopathy (HC) patients who are refractory to medical therapy, the amount of alcohol that is required has not been well studied. This study sought to determine the amount of alcohol that is necessary to achieve clinical benefits of ASA. METHODS: Myocardial perfusion imaging was used to determine the size of the myocardial infarction produced by ASA in 54 HC patients. Left ventricular outflow gradients (LVOTg) were determined invasively before and after ASA and by Doppler echocardiography before and at a median of 3 months after ASA. RESULTS: LVOTg decreased at rest and after provocation in response to ASA and this was maintained on follow-up at 3 months. There was no relationship between the amount of alcohol infused and the infarct mass as determined by myocardial perfusion imaging. While the infarct mass was not correlated with the drop in the LVOTg at rest or with provocation, the quantity of alcohol infused was correlated with the drop in LVOTg at rest (r = 0.27, p = 0.05) and with provocation (r = 0.34, p = 0.02). Furthermore, infusing more than 2ml of absolute alcohol was associated with a drop in the LVOTg by more than 60 mmHg at rest (p = 0.02) and by more than 130 mmHg with provocation (p = 0.05). CONCLUSIONS: Although lower amounts of alcohol infusion are desirable to avoid side-effects, it might be prudent to infuse around 2 ml of absolute alcohol in order to achieve the desirable degree of LVOTg reduction in ASA.

Correlation between serum cardiac markers and myocardial infarct size quantified by myocardial perfusion imaging in patients with hypertrophic cardiomyopathy after alcohol septal ablation.

Myocardial infarct (MI) size is a well-established prognostic marker but the association of serum markers with MI size, as measured by myocardial perfusion imaging (MPI), has not been well studied in patients with hypertrophic cardiomyopathy (HC) after alcohol septal ablation (ASA). Creatine kinase (CK), CK-MB, troponin I, and brain natriuretic peptide were measured before and at multiple points after ASA in patients with HC and were correlated with MI size measured by MPI. MPI at rest was performed in 54 patients with HC at a median of 2 days after ASA. CK, CK-MB, and troponin I increased after ASA to peak levels at 12 hours and their cumulative levels (area under the curve) showed significant correlation with size of MI by MPI (r = 0.544, 0.408, and 0.477, p <0.001, 0.003, and 0.001, respectively). The best marker was level of CK at 12 hours (r = 0.609, p <0.0001) after ASA. Brain natriuretic peptide level did not change significantly after ASA (p = 1.0) and only weakly correlated with MI size by MPI (r = 0.130, p = 0.007). In conclusion, CK, CK-MB, and troponin I measured at 12 hours, at peak, and as the area under the curve correlated well with infarct size, but CK level at 12 hours was the best marker. CK continues to be a useful marker of MI size despite the introduction of newer, more specific markers, especially when infarct onset is known with certainty as in patients with HC undergoing ASA.

The value of live/real time three-dimensional transesophageal echocardiography in the assessment of valvular vegetations.

We studied 13 patients with valvular vegetations who underwent intraoperative live/real time three-dimensional transesophageal echocardiography (3DTEE) and real time two-dimensional transesophageal echocardiography (2DTEE). The 3DTEE provided incremental value on top of 2DTEE in its ability to accurately identify and localize vegetations and in identifying complications of infective endocarditis such as abscesses, perforations, and ruptured chordae. By using 3DTEE, we were able to measure vegetation volumes, perforation areas, and estimate the area of the valve that is involved in the infective process. These preliminary results suggest the superiority of 3DTEE over 2DTEE in the evaluation of valvular vegetations and provide incremental knowledge that is useful to the cardiac surgeons.

Usefulness of live/real time three-dimensional transthoracic echocardiography in diagnosing acquired left ventricular-right atrial communication misdiagnosed as severe pulmonary hypertension by two-dimensional transthoracic echocardiography.

We describe an adult patient with an acquired left ventricular-right atrial communication that was misdiagnosed as severe pulmonary hypertension (PH) by two-dimensional (2D) transthoracic echocardiography, but accurately detected on three-dimensional (3D) transthoracic echocardiography. Open heart surgery confirmed the defect.

Live/real time three-dimensional transthoracic echocardiographic assessment of aortic dissection rupture into right ventricular outflow tract: a case report and review of the literature.

We present a case of chronic ascending thoracic aortic dissection with rupture into the right ventricular outflow tract (RVOT) diagnosed by two-dimensional transthoracic echocardiogram in which live/real time three-dimensional (3D) transthoracic echocardiogram provided incremental value by demonstrating: (a) a tortuous false lumen that encroached and ruptured into the RVOT, (b) exact location of the rupture site in relation to other surrounding structures in 3 dimensions (c) en face view of the rupture site facilitating assessment of its size and shape, and (d) localized compression of the main pulmonary artery (PA) by the false lumen. In addition, cropping of the 3D data set permitted visualization of the origin of the left main coronary in a rapid manner excluding involvement of this vessel with the dissection process. These findings have potential implications for surgical planning and were corroborated by a computed tomography angiogram. We summarize seven previously reported aortic dissection cases with rupture into the right ventricle.

Comparison of real time two-dimensional with live/real time three-dimensional transesophageal echocardiography in the evaluation of mitral valve prolapse and chordae rupture.

We compared live/real time three-dimensional transesophageal echocardiography (3D TEE) with real time two-dimensional transesophageal echocardiography (2D TEE) in the assessment of individual mitral valve (MV) segment/scallop prolapse and associated chordae rupture in 18 adult patients with a flail MV undergoing surgery for mitral regurgitation. 2D TEE was able to diagnose the prolapsing segment/scallop and associated chordae rupture correctly in only 9 of 18 patients when compared to surgery. In three of these, 2D TEE diagnosed an additional segment/scallop not confirmed at surgery. In the remaining nine patients, surgical findings were missed by 2D TEE. On the other hand with 3D TEE, the prolapsed segment/scallop and associated ruptured chords correlated exactly with the surgical findings in the operating room in 16 of 18 patients. The exceptions were two patients. In one, 3D TEE diagnosed prolapse and ruptured chordae of the A3 segment and P3 scallop, while the surgical finding was chordae rupture of the A3 segment but only prolapse without chordae rupture of the P3 scallop. In the other patient, 3D TEE diagnosed prolapse and chordae rupture of P1 scallop and prolapse without chordae rupture of the A1 and A2 segments, while at surgery chordae rupture involved A1, A2, and P1. This preliminary study demonstrates the superiority of 3D TEE over 2D TEE in the evaluation of individual MV segment/scallop prolapse and associated ruptured chordae.

Live/real time three-dimensional transthoracic echocardiographic assessment of pulmonary regurgitation.

There is no gold standard for the measurement of pulmonary regurgitation (PR) severity. Two-dimensional (2D) transthoracic echocardiography is most commonly used to quantify PR severity using color Doppler criteria for aortic regurgitation. However, this method is limited by visualization of only one or two dimensions of the proximal PR jet or vena contracta (VC) precluding accurate assessment of its shape or size. This limitation would be expected to be obviated by three-dimensional (3D) transthoracic echocardiography, which could provide a more accurate quantitative assessment of PR severity. This study evaluated 82 adult patients with PR using 2D and 3D. PR VC area by 3D was obtained by planimetry by positioning the cropping plane exactly parallel to the VC, which was viewed en face by cropping of the 3D data set. Regurgitant volumes were calculated by 2D (assuming a circular VC) and by 3D as a product of the VC and velocity time integral obtained by color Doppler-guided conventional Doppler interrogation of the PR jet.The 3D VC area correlated with 2D jet width (JW)/right ventricular outflow tract (RVOT) width (r = 0.71) and 2D VC area (r = 0.79). 3D JW/RVOT width correlated with 2D JW/RVOT (r = 0.87). 3D regurgitant volumes also correlated with 2D regurgitant volumes (r = 0.76). The 3D VC values of <0.20, 0.20-0.45, 0.46-1.15, and >1.15 cm(2) and regurgitant volumes of <15 ml, 15-50 ml, 51-115 ml, and >115 ml were effective as cutoffs for grades 1, 2, 3, and 4 PR, respectively. In conclusion, quantification of 3D VC area and regurgitant volumes correlate reasonably well with the current 2D methods for measurement of PR. Since 3D visualizes PR VC in three dimensions, it would be expected to provide a more accurate and more quantitative assessment of PR severity as compared to 2D.