Intravascular ultrasound of the elastic pulmonary arteries: a new approach for the evaluation of primary pulmonary hypertension.

OBJECTIVE: To assess the structural and functional characteristics of pulmonary arteries by intravascular ultrasound (IVUS) in the setting of primary pulmonary hypertension, and to correlate the ultrasound findings with haemodynamic variables and mortality at follow up. DESIGN: Prospective observational study. SETTING: University hospital (tertiary referral centre). PATIENTS: 20 consecutive patients with primary pulmonary hypertension (16 female; mean (SD) age, 39 (14) years). METHODS: Cardiac catheterisation and simultaneous IVUS of pulmonary artery branches at baseline and after infusion of epoprostenol. RESULTS: 33 pulmonary arteries with a mean diameter of 3.91 (0.80) mm were imaged, and wall thickening was observed in all cases, 64% being eccentric. Mean wall thickness was 0.37 (0.13) mm, percentage wall area 31.0 (9.3)%, pulsatility 14.6 (4.8)%, and pulmonary/elastic strain index 449 (174) mm Hg. No correlation was observed between IVUS findings and haemodynamic variables. Epoprostenol infusion increased pulsatility by 53% and decreased the pulmonary/elastic strain index by 41% (p = 0.0001), irrespective of haemodynamic changes. At 18 (12) months follow up, nine patients had died. A reduced pulsatility and an increased pulmonary/elastic strain index were associated with increased mortality at follow up (12.0 (4.4)% v 16.4 (4.4)%, p = 0.03; 369 (67) v 546 (216) mm Hg, p = 0.02). CONCLUSIONS: IVUS demonstrated pulmonary artery wall abnormalities in all patients with primary pulmonary hypertension, mostly eccentric. The severity of the changes did not correlate with haemodynamic variables, and epoprostenol improved pulmonary vessel stiffness. There was an association between impaired pulmonary artery functional state as determined by IVUS and mortality at follow up.

Frequency and clinical significance of myocardial ischemia detected early after coronary stent implantation.

UNLABELLED: A high number (30%-50%) of reversible defects have been detected early after coronary balloon angioplasty. Inadequate luminal enlargement despite a good angiographic appearance has been suggested as a possible mechanism of these perfusion abnormalities, and some reports have shown better coronary flow reserve after coronary stent implantation than after balloon dilatation. The primary objective of this study was to evaluate the frequency of early ischemic defects detected by maximal exercise (plus dipyridamole) with (99m)Tc-tetrofosmin SPECT after successful coronary angioplasty with stent implantation. A secondary objective was to determine the prognostic value of these early ischemic defects. METHODS: Thirty patients without previous myocardial infarction who successfully underwent 1-vessel coronary angioplasty with stent implantation were studied. Maximal-exercise (99m)Tc-tetrofosmin myocardial SPECT, with simultaneous dipyridamole if exercise was suboptimal, was performed at 6 +/- 1 d (mean +/- SD) after percutaneous transluminal coronary angioplasty. At 8 +/- 3 mo, all patients were followed up clinically, and 77% of them underwent follow-up angiography. RESULTS: The percentage of stenosis decreased from 68.5% +/- 12.6% of luminal diameter to 9.3% +/- 8.8% after stent implantation, and minimal luminal diameter increased from 0.89 +/- 0.36 mm to 2.85 +/- 0.45 mm. Mild-to-moderate reversible myocardial defects in the territory of the dilated artery were detected in 5 patients (17%), with no angiographic or procedural differences occurring between them and patients without ischemic defects. At follow-up, the target lesion revascularization rates depending on the presence or absence of early ischemic defects were 40% and 8%, respectively (P = 0.18). Angiographic restenosis occurred in 3 of 4 patients who had early ischemic defects and underwent follow-up angiography and in 3 of 19 patients who had no early ischemic defects and underwent follow-up angiography (restenosis rate, 75% and 16%, respectively; P < 0.05). CONCLUSION: Coronary angioplasty with stent implantation is associated with a 17% rate of ischemic defects early after the procedure. Patients with early myocardial perfusion defects after coronary stent implantation had a high rate of restenosis.

Percutaneous electrocatheter technique for on-line detection of healed transmural myocardial infarction.

Healed myocardial infarction has been recognized by its particular tissue electrical impedance spectrum measured with intramural needle electrodes in animal models. The aim of this study was to develop a percutaneous approach for in vivo recognition of areas of healed myocardial infarction by measuring myocardial electrical impedance with an intracavitary contact electrocatheter. Electrical impedance (resistance and phase angle) of normal myocardium and of a 2-month-old anterior transmural infarction were measured in nine chloralose anesthetized pigs by applying alternating currents from 1 kHz to 1 MHZ between a bipolar intracavitary catheter and a reference electrode placed on the epicardium (group I, n = 4) or on the precordium (group II, n = 5). Resistance of the infarcted myocardium was lower than that of healthy tissue at all current frequencies (ANOVA, P < 0.001) (i.e., at 1 kHz: 15 +/- 4 omega vs 50 +/- 19 omega in group I, and 64 +/- 13 omega vs 76 +/- 13 omega in group II). Phase angle at 316 kHz best differentiated transmural infarction from normal tissue (group I: -2.5 +/- 1.9 degrees vs -14.8 +/- 4.6 degrees, P < 0.001; group II: +0.7 +/- 1.0 degrees vs -2.7 +/- 1.4 degrees, P < 0.001). This study shows that analysis of myocardial impedance spectrum using a percutaneous intracavitary contact catheter approach permits on-line recognition of areas of healed transmural myocardial infarction. This technique may be useful to optimize clinical application of energy sources (i.e., radiofrequency ablation, laser myocardial revascularization).

Neurally mediated depressor hemodynamic response induced by intracoronary catheter balloon inflation in pigs.

OBJECTIVES: To assess whether intracoronary catheter balloon inflation triggers a neurally mediated hemodynamic response that interacts with the ischemia-induced myocardial dysfunction. METHODS: Forty-eight chloralose anesthetized pigs underwent a 60 s intraluminal catheter balloon inflation of the proximal left anterior descending (LAD) coronary artery before and after one of these treatments: disruption of LAD pericoronary nerves with phenol (n=6), bilateral stellectomy (n=8), bilateral cervical vagotomy (n=6), atropine (n=5), and ganglionic blockade with hexamethonium (n=10). In 13 other pigs, we assessed the reproducibility of two balloon inflations spaced 15 min (n=6) or 60 min (n=7). The ECG, left ventricular (LV) pressure, and LV dP/dt were recorded during each intervention. Right ventricular (RV) pressure, RV dP/dt, and aortic blood flow were also measured in a subset of pigs. RESULTS: Balloon inflation induced an early (10 s) and reproducible (ANOVA, P<0.001) drop in systolic pressure and peak dP/dt; a decrease in aortic blood flow; a rise in end-diastolic pressure; and elevation of the ST segment. Pericoronary denervation, stellectomy and ganglionic blockade attenuated (P<0.001) the drop in LV parameters during coronary inflation, but atropine and vagotomy did not. CONCLUSIONS: A depressor hemodynamic response subserved by pericoronary nerves worsens the LV dysfunction induced by brief coronary catheter balloon inflation in anesthetized pigs. Cholinergic fibers do not appear to play a major role.

[Refractory angina caused by steal phenomenon in internal mammary artery resolved with embolization]. / Angina refractaria por fenómeno de robo en arteria mamaria interna resuelta mediante embolización.

We report a patient with refractory angina in the postoperative period of a coronary artery bypass grafting. Ischemia was due to a large side branch of the left internal mammary artery causing steal phenomenon that was treated with transcatheter coil embolization.

[Diagnostic efficacy of myocardial tomographic imaging in the detection of restenosis after coronary angioplasty]. / Eficacia diagnóstica de la tomogammagrafía miocárdica en la detección de reestenosis coronaria postangioplastia.

INTRODUCTION AND OBJECTIVES: To analyze the efficacy of single photon emission tomography (SPET) with 99mTc-compounds for the diagnosis of restenosis of previous percutaneous transluminal coronary angioplasty (PTCA). PATIENTS AND METHODS: Seventy-one patients (16 women, median age: 60 years, 35 with multivessel disease, 78 arteries with PTCA) with previous PTCA and with coronary angiography performed after scintigraphy were studied. 99mTc-SPET exercise (53 with MIBI and 18 with tetrofosmin) was performed, for clinical reasons, to all patients between one month and 4 years after PTCA. Intravenous dipyridamole was administered simultaneously to 16 patients who had insufficient exercise. RESULTS: SPET sensitivity, specificity, positive predictive values, negative predictive values and global values were all significantly higher than those obtained with exercise tests (80% vs 63%; p = 0.05; 83% vs 37%; p = 0.001; 91% vs 69%; p = 0.007; 64% vs 31%; p = 0.009, and 81% vs 55%; p = 0.0006, respectively). These results were significantly superior in patients with one vessel disease than in patients with multivessel disease. CONCLUSIONS: SPET exercise with 99mTc-compounds is a test with a high efficacy for the diagnosis of post-PTCA restenosis, mainly in patients with one vessel disease.

[De-novo reversible stenoses in tortuous arteries during coronary angioplasty due to the accordion effect. A clinical case and review of the literature]. / Estenoses de novo reversíveis em artérias tortuosas durante a angioplastia coronária devido ao efeito de acordeão. Caso clínico e revisão da literatura.

During the performance of PTCA, the operator must be able to differentiate true complications from pseudocomplications. Mechanical coronary shortening and vessel wall invagination due to accordion effect, "pseudo-transection", dissection, coronary spasm, and localized thrombosis are sources of iatrogenic obstruction during angioplasty. We report a case in which straightening of a right tortuous coronary artery during angioplasty produced an iatrogenic lesion that has a typical invaginate appearance. Conservative management is indicated in the absence of definitive angiographic aspect of vessel trauma, because they disappear after withdrawal of angioplasty equipment or adequate management of the guidewire.

[Transesophageal echocardiography in the diagnosis of aortic dissection]. / Ecocardiografía transesofágica en el diagnóstico de la disección aórtica.

INTRODUCTION AND OBJECTIVE: Eighty-two patients with suspected aortic dissection were studied to assess the usefulness of transesophageal echocardiography in the diagnosis of this entity. METHODS: All patients underwent transesophageal echocardiogram. The diagnosis of aortic dissection was established in 46 patients by other diagnostic procedures including angiography and computed tomography, surgery and necropsy. RESULTS: The sensitivity and specificity of transesophageal echocardiography were 98% and 97%, respectively. By computed tomography, sensitivity was 92% and specificity 88%. By angiography, sensitivity and specificity were 97% and 93%, respectively. In the diagnosis of the dissection type, transesophageal echocardiography classified correctly in 98%, computed tomography in 89% and angiography 97% of cases. Transesophageal echocardiography visualized the tear in 82% of cases, and angiography in 53%. CONCLUSIONS: Transesophageal echocardiography provides rapid, accurate diagnosis of aortic dissection and permits the initiation of appropriate treatment. Angiography is indicated in non-conclusive cases or those which supra-aortic involvement clinically suspected.

[The usefulness of Doppler echocardiography in the preoperative assessment of valvulopathies. A comparison with the hemodynamic and surgical findings]. / Utilidad de la ecocardiografía-Doppler en la evaluación prequirúrgica de las valvulopatías. Comparación con los hallazgos hemodinámicos y quirúrgicos.

The Doppler echocardiography and cardiac catheterization studies of all patients who underwent valvular surgery in a three-year period were reviewed to assess the correlation between the estimated severity of valvular disease by both methods. Two-hundred and thirty-five patients (group I: 140 male, age 58 +/- 12; 95 female, age 60 +/- 13) underwent both studies within 6 months. There was agreement on estimation of severity of valve lesions in 140 of 162 patients with aortic valve disease (93% of stenosis, 82% of regurgitations and 79% of mixed lesions), in 58 of 80 patients with mitral valve disease (83% of stenosis, 76% of regurgitations and 33% of mixed lesions) and in 10 of 16 patients with prosthetic valve disfunction. The correlation between both methods was significantly lower in mixed mitral lesions than in the remaining native valve lesions (p < 0.05). Significant disagreement occurred in 4 cases of aortic valve disease, four of mitral valve disease and five of prosthetic disfunction. When disagreement was present, Doppler often underestimated the severity of the disease. Disagreement was more frequent in patients with combined aortic and mitral disease. According to the surgical conclusions cardiac catheterization provided a diagnostic profit in the assessment of the disease severity in 8, 11 and 22% of cases of aortic and mitral valve disease and prosthetic valve disfunction, respectively. Coronary artery disease was present in 19% of patients who underwent coronary arteriography. One-hundred and two patients (group II: 44 m, 48 +/- 15; 58 f, 53 +/- 11) underwent surgery without previous cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical and angiographic course after coronary angioplasty. Analysis of predictor factors of restenosis]. / Evolución clínica y angiográfica postangioplastia coronaria. Análisis de factores predictores de reestenosis.

In order to know the restenosis rate and its predictive factors and the short-term clinical outcome (6-12 months) after coronary angioplasty (PTCA), we prospectively followed 200 consecutive patients with 231 coronary stenoses successfully dilated (residual stenosis < 50%). Patients have been clinically and angiographically followed 6-9 months after the procedure. Forty-nine clinical, hemodynamic, angiographic and technical variables were analyzed. Restenosis (stenosis > or = 50% in late angiographic control) rate was 51.5%, and 61% of the study population was symptomless. Variables associated with restenosis in the univariate analysis were: pre-PTCA positive exercise test (p = 0.004); stenosis severity pre-PTCA (p = 0.04); eccentricity (p < 0.0001) and irregularity (p < 0.0001) of the pre-PTCA stenosis; total dilation time (p = 0.02) and post-PTCA dissection (p = 0.002). The multivariate analysis revealed the following variables as independent predictors of restenosis: presence of dissection after PTCA, eccentricity and irregularity of pre-PTCA stenosis, positive pre-PTCA stress test and duration of symptoms before the procedure. These data suggest that the probability of restenosis after PTCA is predominantly determined by the characteristics of the lesion being dilated and the degree of intimal injury produced during the procedure. These variables could define high and low risk populations and may modify PTCA indications and follow up strategies.

Percutaneous right brachial artery approach with 5F catheters for studying coronary artery disease.

We prospectively studied 60 ischemic patients with 5F catheters (Pigtail and Amplatz) using the percutaneous right brachial artery approach (group I), in order to compare this technique with two groups of 100 patients each randomly studied by the femoral route with either 5F (group II) or 8F (group III) catheters (Pigtail and Judkins). The following parameters were analyzed: need to change the initially elected catheter diameter or/and artery approach; technical difficulty for obtaining LV, LCA, and RCA angiograms; total time of X-ray exposure; quality image of LV, LCA, and RCA angiograms; incidence of arterial puncture related hematomas or total arterial occlusion; and duration of local compression after sheath removal. There were no differences between 5F brachial and femoral approaches except for the arterial compression time (p less than 0.01) and the X-ray exposure time (p = 0.03) which were longer with the brachial approach. Whatever the route used, 5F showed a mild increase difficulty (brachial p = 0.001; femoral p = 0.01) and a mild decreased quality image for LCA (branchial p = 0.006; femoral p less than 0.05). Mild hematomas were more frequent with 8F catheters (p less than 0.05). The procedure could be completed by the elected first artery and type of catheter (5F or 8F) in 57/60 patients in group I, in 95/100 in group II, and in 96/100 in group III (nonsignificant differences). Thus, the percutaneous right brachial artery approach using 5F catheters is similar to the femoral artery approach with the same catheters. Although both of them showed a mild increased technical difficulty and a mild decreased quality image compared to 8F, mainly for LCA angiograms, they allowed complete and reliable angiograms reading and analysis.

[Coronarography using high-flow 5F catheters. Percutaneous technic using the femoral and brachial routes]. / Coronariografía con catéteres 5F de alto flujo. Técnica percutánea por vías femoral y braquial.

In order to validate 5F catheters for assessing ischemic heart disease either by the femoral and the right brachial approaches, we prospectively studied with these catheters 125 patients by means of left ventriculogram and coronary artery angiograms. Twenty-five patients were studied with pigtail and Amplatz catheters using the right brachial approach (group I) and 100 patients were studied by the femoral route with pigtail and Judkins catheters (group II). Results were compared to those obtained in a control group of 100 patients prospectively studied by the femoral route with 8F catheters (group III). The following parameters were analyzed: need to change the initially elected catheter diameter or/and artery approach; technical difficulty for obtaining left ventriculogram, left coronary artery, and right coronary artery angiograms; total time of X-ray exposure; quality image of left ventriculograms; incidence of arterial puncture related hematomas or total arterial occlusion; and duration of local compression after sheath removal. There were no differences between groups I and II except for the arterial compression time (p less than 0.0001), and the X-ray exposure time (p = 0.02); both were longer in patients studied by the brachial approach (group I). Whatever the route used, 5F showed a mild increased difficulty (brachial p = 0.001; femoral p = 0.01), and a mild decreased quality image for left coronary artery (brachial p = 0.006; femoral p less than 0.05). Among patients studied by the femoral route a reduction in mild hematomas (p less than 0.05) and in the arterial compression time (p less than 0.0001) were observed in those studied with 5F catheters.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of small branch occlusion and myocardial damage related to angioplasty. Usefulness of determining serum CK-MB]. / Valoración de la oclusión de ramificaciones y daño miocárdico relacionados con la angioplastia. Utilidad de las determinaciones de CK-MB sérica.

In 65 consecutive cases of PTCA we prospectively looked for the appearance of myocardial necrosis during PTCA and for the presence of occlusion of collateral branches arising from the inflation area. Premedication was oral in 44 and intramuscular in 21 cases. CK-MB was abnormally increased in 6 cases: 3 with total occlusion of the dilated artery, 1 with transient coronary occlusion, and 1 with occlusion of a collateral branch greater than 1 mm diameter; in the sixth case the increased CK-MB peak was attributed to repeated defibrillations. Only 1 collateral branch less than 1 mm was occluded during PTCA though myocardial necrosis was not detected. Only collateral branches arising from the dilated stenosis were affected (occlusion and/or appearance of new stenosis) by PTCA (4/24 vs 0/162; p less than 0.01). There were no significant differences in CK-MB peak between both types of premedication. Thus we conclude that: 1) in PTCA myocardial necrosis is only induced by occlusion of coronary arteries greater than 1 mm diameter; 2) only collateral branches arising from the dilated stenosis are at risk of occlusion; 3) estimation of CK-MB pre-PTCA and 8 hours post-PTCA are sufficient for detection of myocardial necrosis.

Differences of postextrasystolic behavior of left ventricular and aortic pressures between fixed and dynamic left ventricular outflow tract stenosis.

The dynamic behavior of fixed LV outflow tract stenosis partly resembles that of OCM. To analyze their differences we studied basal and postextrasystolic (post-PVC) peak-to-peak LV aortic gradients, aortic systolic pressure, and pulse pressure in 14 OCM and in 36 pure VAS without two-dimensional echocardiographic findings of OCM. Fifteen mild VAS had basal gradients similar to those of OCM (39 +/- 17 mm Hg vs 24 +/- 16 mm Hg). Patients with OCM show a post-PVC gradient (109 +/- 41 mm Hg) similar to that of VAS (110 +/- 50 mm Hg). However, the latter were departing from much higher gradients (VAS 72 +/- 30 mm Hg vs OCM 24 +/- 16 mm Hg). Decrement of post-PVC aortic systolic pressure and pulse pressure were frequent in both groups, but decrement of pulse pressure greater than 5 mm Hg were more frequent in OCM. We concluded that (1) post-PVC increased aortic gradients and decreased aortic systolic pressure occurred in both VAS and OCM; (2) post-PVC decreased aortic pulse pressure might occur in VAS; and (3) association of post-PVC gradient increment greater than 75 percent and pulse pressure decrement greater than 5 mm Hg are strongly suggestive of OCM.

Five French versus eight French catheters and the Judkins technique. Advantages and limitations for studying coronary artery disease.

In order to compare 5 French versus 8 French catheters for assessing ischemic heart disease, we prospectively studied 2 groups of 100 patients each, one with 5 French (group I) and the other with 8 French (group II) catheters by the Judkins technique. Significant differences were found in the greater easiness to catheterize LV (p less than 0.05) and LCA (p = 0.01) in group II and in better quality image for LCA in group II (p less than 0.05), although all patients in both groups had acceptable image quality. Pressure curves quality was better in group II (p less than 0.01); X-ray exposure time was longer in group I (p less than 0.001) and arterial compression time in group II (p less than 0.0001). Group I showed 3 and group II 10 mild hematomas (p less than 0.05). The procedure could be completed by the elected first artery and type of catheter in 95 patients in group I and in 96 in group II. Thus, the Judkins technique with 5 French catheters is as valid as with 8 French for assessing ischemic patients, reducing arterial morbidity, although mildly increasing technical difficulty and mildly decreasing quality image.

Postextrasystolic potentiation of systolic gradient in valvular aortic stenosis: clinical usefulness and analysis of hemodynamic factors.

To analyze the behavior of aortic valve gradient (AVG) after ventricular extrasystole (VE), we studied 36 pure valvular aortic stenoses (AS) free of coronary artery disease and obstructive hypertrophic cardiomyopathy, in whom basal (B) (74 +/- 32 mm Hg) and catheter-induced post-VE (110 +/- 50 mm Hg) AVG were obtained. In all 26 cases with valve area less than 0.70 cm2, the post-VE AVG was greater than or equal to 70 mm Hg. In 19 cases AVG after two or more consecutive VE were also obtained. Maximal post-VE AVG was obtained after multiple VE (19 cases) and/or after one VE causing a post-VE pause equal or longer than 1.7 basal cardiac cycles (post-VE RR greater than or equal to 1.7 B RR) (9 cases). Basal and postsingle VE AVG, up to a post-VE RR greater than or equal to 1.7 B RR, were a linear function of previous RR (r greater than or equal to 0.90), regression line slope increasing with AS severity (P = .05). Inotropic state measured by PEP/LVET only increased after multiple VE, P less than .01. AVG after multiple VE was independent of post-VE RR. Thus, 1) post-VE potentiation of AVG may be seen with fixed valvular AS without obstructive cardiomyopathy; 2) post-VE AVG is a function of compensatory pause after single VE and of increased inotropism after multiple VE; 3) analysis of maximal post-VE AVG generated as described is reliable and useful for assessing AS severity (post-VE AVG greater than or equal to 70 mm Hg meaning an aortic valve area less than 0.70 cm2) and may supplement valve area calculations.