Assessing myocardial viability using the coronary flow response to intravenous dobutamine infusion in recent myocardial infarction.

Coronary flow response to low-dose (5 and 10 micrograms/kg/min) dobutamine infusion was used to assess myocardial viability at the time of cardiac catheterization in 13 patients (age, 60 +/- 11 years) with recent myocardial infarction. Echocardiographic improvement in regional wall motion performed 4 to 6 weeks after discharge was used as the marker for viability. Viable patients demonstrated a 2-fold increase in flow from baseline (p < 0.001) during intravenous infusion. In contrast, patients without viability demonstrated no increase in flow. The coronary flow response to dobutamine measured at the time of catheterization shows promise in identifying viable myocardium in postinfarction patients.

Novel approach to rotational atherectomy results in low restenosis rates in long, calcified lesions: long-term results of the San Antonio Rotablator Study (SARS).

Ablation technique and adjunctive strategy may affect restenosis after rotational atherectomy. To minimize trauma to the vascular wall, we changed the technique of rotablation as follows: the RPM range was decreased to 140,000-160,000 RPM, the ablation was performed using a repetitive pecking motion, avoiding a decrease in the rotational speed of the burr greater than 3,000 RPM, long lesions were divided into segments and each segment was separately ablated, and the burr-to-artery ratio was intended to be approximately 0.75. To prevent coronary spasm, before and after each pass, 100-200 microg nitroglycerin and 100-200 microg verapamil i.c. boluses were administered. Adjunctive PTCA was performed using a closely sized 1.1:1 balloon-to-artery ratio with a noncompliant balloon at low pressures for 120 sec. The study incorporated 111 patients with a combined total of 146 calcified lesions. Results. A total of 31.5% of patients underwent a multivessel procedure. No deaths occurred. Q-wave MI and/or creatine kinase elevation greater than three times baseline levels occurred in 4.5% of patients. By quantitative coronary angiography (QCA), the reference vessel diameter was 3.13+/-0.59 mm, mean lesion length was 33.41+/-18.58 mm. Percent stenosis and mean luminal diameter were as follows: at baseline 75.7%+/-10.8%, or 0.76+/-0.41mm, Post-rotational atherectomy 41.5%+/-3.6%, or 1.83+/-0.43 mm, Post-PTCA 18.2%+/-11.9%, or 2.56+/-0.50 mm. Six-month angiographic follow-up was available in 64 (57.7%) pts. Net luminal gain was 1.15+/-0.76 mm, with a late luminal loss of 0.65+/-0.84 mm. The mean diameter stenosis at follow-up was 37.6%+/-28.5%, with MLD 1.91+/-1.21 mm. The binary restenosis rate was 28.1%. Therefore, modification of rotational atherectomy technique with adjunctive PTCA resulted in a favorable restenosis rate in long, calcified lesions. Cathet. Cardiovasc. Intervent. 48:48-53, 1999.

Coronary steal by IMA bypass graft side-branches: a novel therapeutic use of a new detachable embolization coil.

Coronary artery steal syndromes following coronary artery bypass grafting (CAB) may occur as a result of the presence of large side-branches arising from the internal mammary artery (IMA). We report the first successful deployment of a new detachable vascular embolization coil device to occlude the IMA side-branches in two patients. Optimal positioning is easily obtained with the unique operator-controlled, safety-release protected mechanism of this device. Complete retraction is possible, with safe and efficient removal of the coil even after deployment. This feature was appreciated during one procedure in which the initially selected coil was found to be oversized, requiring immediate removal. Acute thrombo-occlusion of the IMA side-branches in both patients was observed. We conclude that IMA bypass graft side-branches causing coronary steal can be safely and effectively occluded using this new technique. However, due to observed delayed partial recanalization noted on distant follow-up angiography, we recommend placement of multiple coils at the time of initial embolization.

Acute directional coronary atherectomy prior to stenting in complex coronary lesions: ADAPTS Study.

The purpose of this study was to determine the results of directional coronary atherectomy (DCA) combined with stenting in a high-risk patient population. The use of stenting or DCA alone for aorto-ostial lesions, total chronic occlusions, long lesions, and lesions containing thrombus is associated with lowered success and a relatively high restenosis rate. Between July 1993 and October 1996, we treated 89 lesions with the combined approach of DCA and stenting in 60 consecutive patients. Thirty-one (51.7%) patients were treated because of unstable angina, 11 (18.3%) for post-myocardial infarction (MI) angina, 3 (5.0%) for acute MI, and 15 (25.0%) patients for stable angina. A total of 43 (71.7%) patients had multivessel disease, 19 (31.7%) had undergone previous coronary artery bypass graft (CABG), and 17 (28.3%) patients had undergone multivessel revascularization. The procedure was successful in all patients; and no postprocedural deaths or emergent CABG occurred. Two patients (3.3%) had non-Q-wave MI after the procedure and 1 patient (1.7%) experienced Q-wave MI due to subacute stent closure 7 days after the procedure. During follow-up ranging from 6 months to 3 years, 2 (3.3%) patients died, 2 (3.3%) required CABG surgery, 1 (1.7%) patient had an MI, and 6 patients (10.0%) required target vessel revascularization. By the quantitative coronary angiography, the initial minimal luminal diameter (MLD) averaged 0.91+/-0.45 mm (74.7+/-11.8% stenosis) increasing to 3.80+/-0.44 mm (-6.7+/-12.1%) after the combined approach procedure. Thirty patients (50.0%) met criteria for late (> or =6 months) angiographic follow-up. Late MLD loss averaged 1.13+/-1.07 mm, for a mean net gain of 1.61+/-1.23 mm. Available angiographic follow-up evaluation showed a restenosis rate of 13.3%. A combined approach, defined as the use of both DCA and stenting, is safe and yields a low restenosis rate in high-risk patients who have lesions known to respond less favorably to stenting or DCA alone.

Variation of flow propagation velocity with age.

Flow propagation velocity is a new color Doppler M-mode measurement of left ventricular filling characteristics. This study was designed to establish normal values for this measurement in healthy individuals and to compare these findings with pulsed Doppler transmitral velocities. Complete M-mode, two-dimensional, and Doppler echocardiographic studies were performed on 64 volunteers between 21 and 79 years of age. Significant negative correlations (p < 0.001) with age were noted for flow propagation velocity (r = -0.59), peak early diastolic filling velocity (r = -0.65), and peak early diastolic filling/peak atrial filling ratio (r = -0.80). Positive correlations (p < 0.001) with age were observed for peak atrial filling velocity (r = 0.50) and atrial filling velocity integral (r = 0.71). Flow propagation velocity decreased by 44% between the youngest and oldest age groups. We conclude that flow propagation velocity is influenced by age and that it compares favorably with transmitral Doppler indices of left ventricular filling in this regard. These age-related alterations are present in healthy individuals, in the absence of any apparent cardiovascular disease.

Doppler echocardiography in cardiac transplant patients: allograft rejection and its relationship to diastolic function.

Right ventricular endomyocardial biopsy has been the traditional gold standard for determining cardiac transplant rejection. Although endomyocardial biopsy has proved useful in guiding rejection therapy, this procedure is not without risk. The objective of the present study was to determine whether a noninvasive method for assessing cardiac diastolic function would be of value in predicting biopsy scores. Doppler echocardiographic indices of left ventricular function were compared with biopsy scores in 43 studies from 23 patients (age 50 +/- 8 years). The average time from transplant to echocardiographic study was 1.5 years. Standard clinical indices of diastolic function failed to predict biopsy results. The A-Ar interval, evaluated in 36 studies, was found to significantly decrease (p < 0.003) with increasing biopsy scores. Preliminary results suggest that this echocardiographic parameter may prove useful in predicting biopsy results.

Applications of a novel balloon catheter during coronary angioplasty.

A new balloon catheter design utilizing multiple polymeric materials to produce noncompliant balloon ends and a compliant central portion has recently been released. We describe two cases, a discrete fibrotic lesion and final dilation of an intracoronary stent, in which this novel balloon catheter has potential advantages during coronary angioplasty. We conclude that this device may be useful in avoiding proximal or distal vessel dissection during high-pressure balloon inflations.

Validation of a new Doppler-echocardiographic method for quantifying mitral regurgitation.

The noninvasive determination of severity of mitral regurgitation (MR) is often of major clinical importance. We performed simultaneous Doppler echocardiography and left ventricular angiography in 24 patients with MR, comparing a new Doppler echocardiographic technique with angiographic criteria for severity of MR. Angiographic severity was measured on a 1+ to 4+ scale, determined by the degree of opacification of the left atrium during left ventricular systole. The echocardiographic examination consisted of color flow imaging and continuous-wave Doppler echocardiography across the mitral valve. The product of the mitral regurgitant color flow jet area and the mitral regurgitant time-velocity integral was obtained, yielding a Doppler-derived regurgitant volume across the mitral valve. Good correlations were demonstrated between the severity of angiographic MR and the Doppler-derived regurgitant volume (r = 0.831; p < 0.005) and between the angiographic severity of MR and the Doppler-determined mitral regurgitant jet diameter (r = 0.833; p < 0.005). We conclude that a new Doppler echocardiographic method for quantitating the severity of MR correlates well with qualitative angiographic grading. Further study is needed to compare this technique with other quantitative Doppler indexes of severity of MR.

Clinical evaluation of a rapid immunoinhibition assay for creatine kinase-MB in suspected myocardial infarction.

We examined the clinical performance of a new immunoinhibition assay (INH) for the measurement of creatine kinase isoenzyme MB (CK-MB). In 196 consecutive patients admitted for exclusion of acute myocardial infarction, serial blood samples were evaluated by INH, immunoradiometric assay (IRMA), and electrophoresis (ELP). Using receiver operating characteristic curve analysis, the diagnostic performance of the INH assay was comparable to IRMA and ELP. As compared with these alternative methodologies, this newly available INH assay for CK-MB provides similar diagnostic accuracy and increased convenience at a greatly reduced cost.

Pharmacodynamic Doppler determination of mitral valve area in patients with significant aortic regurgitation.

In patients with combined mitral stenosis (MS) and aortic regurgitation (AR), the Doppler-determined mitral valve area (MVA) may be overestimated due to a shorter than expected pressure half-time. We performed Doppler echocardiography at baseline and after inhalation of amyl nitrite in 10 patients with combined MS and AR (Group I) and in five patients with MS alone (Group II). AR severity was reduced by amyl nitrite inhalation in all Group I patients, with a decrease in mean jet height/LVOT ratio from 32% to 21% (p < 0.01). Pressure half-time increased in Group I after amyl nitrite, with a mean reduction in the calculated MVA of 0.15 cm2 (p < 0.01). Group II had no significant changes in pressure half-time or Doppler-determined MVA after amyl nitrite, whereas both groups had comparable increases in heart rate, mean transmitral velocity, and mean transmitral pressure gradient. In patients with combined MS and AR, we conclude that amyl nitrite significantly increases pressure half-time while reducing the severity of AR. These findings support earlier reports of MVA overestimation when pressure half-time is used in the presence of AR.

Transdermal scopolamine as a cause of transient psychosis in two elderly patients.

We have described two elderly patients who had psychosis after beginning transdermal scopolamine therapy. In both cases, changes in mental status resolved promptly when the medication was discontinued.