Noninvasive assessment of left and right internal mammary artery graft patency with high-frequency transthoracic echocardiography.

OBJECTIVES: The aim of this study was (1) to visualize internal mammary artery grafts (IMAG) on coronary artery by transthoracic echocardiography and (2) to assess the patency of the grafts. METHODS: Twenty-three patients (21 men, 56 +/- 6 years) with previous coronary artery bypass grafting were studied at baseline and after they underwent low-dose dipyridamole infusion. The parameters obtained were systolic (SPV) and diastolic (DPV) peak velocities and their ratio (DPV/SPV); the dipyridamole infusion to baseline ratio of DPV was an index of IMAG blood flow reserve (FR). Two groups of patients were selected at baseline: group A, (n = 12) with a DPV/SPV >1, and group B (n = 11), with a DPV/SPV <1. RESULTS: The IMAG was identified in all patients. Intraluminal flow signals obtained with pulsed wave Doppler showed a biphasic pattern (1 systolic and 1 diastolic wave). After dipyridamole infusion was administered, flow velocities increased in 11 of 12 patients in group A and in 5 of 11 patients in group B. In group A the DPV/SPV increased from 1.79 +/- 0.47 to 1.8 +/- 0.43 (P = not significant), and the FR was 1.8 +/- 0.4. In group B the DPV/SPV increased from 0. 46 +/- 0.05 to 0.5 +/- 0.09 (P = not significant), and the FR was 1. 3 +/- 0.41. Coronary angiography showed the graft patency in all patients in group A and in 5 patients in group B with increased flow velocity after dipyridamole infusion. In the identification of graft stenosis at baseline, DPV/SPV showed 100% sensibility and 58% specificity, and FR showed 92% sensibility and 84% specificity. CONCLUSION: Doppler echocardiographic evaluation of the IMAG is a simple noninvasive method to assess the functional impairment of the vessel.

Percutaneous mitral commissurotomy versus open mitral commissurotomy: a comparative study.

OBJECTIVE: Although many studies in medical literature are comparing percutaneous trans-septal mitral commissurotomy (PTMC) and open mitral commissurotomy (OMC), very few long-term comparative follow-ups are available. METHODS: Between January 1991 and December 1997, 193 patients with isolated mitral stenosis were assigned either to PTMC (111 cases) or to OMC (82 cases). PTMC was performed in all cases with Inoue Ballon, OMC was performed with standard techniques. Categorical values were compared by chi square analysis, whereas continuous data were compared by Mann-Whitney test. Univariate survival and event free analysis (Kaplan-Meier+/-SE and log rank) were performed. Recurrent stenosis was classified any mitral valve area (MVA) less than 1.2 cm2 and whenever post-op. echo showed a loss more than 50% of the initial gain. Data were reported as mean+/-SD. Data concerning late echocardiographic assessment were studied with linear and logistic regression analysis. RESULTS: The two groups were homogenous as far preoperative variables as sex, mean age, MVA, echo score and incidence of left atrial thrombosis were concerned. Mean NYHA was preoperatively higher in OMC (2.79+/-0.58) versus PTMC (2.42+/-0.5) (P = 0.001). There was no hospital mortality in both groups. Incidence of hospital complications was similar (4/ 111 after PTMC and 1/82 after OMC; P = 0.3). Seven year survival: 95.41+/-0.02 (PTMC) and 98.05+/-0.01 (OMC) (P = 0.3) and freedom from late complications did not show statistical differences: Embolism 98.78+/-0.01 in PTMC and 98.78+0.01 in OMC (P = 0.8); Recurrent stenosis 71.89+/-0.13 in PTMC versus 82.89+/-0.08 in OMC (P = 0.2); Reoperation 88.43+/-0.08 in PTMC versus 96.25+/-0.02 in OMC (P = 0.4). A larger MVA was found in patients undergone to OMC (2.05+/-0.35) versus PTMC (1.81+/-0.33) (P = 0.001). Furthermore mean NYHA was lower in OMC (1.14+/-0.3) versus PTMC (1.39+/-0.7) (P = 0.001). CONCLUSIONS: Both techniques achieve with a low operative risk and low incidence of complications a good palliation of rheumatic mitral stenosis. Incidence of complications in the follow-up is similar. OMC allows a larger mitral valve area, a better functional recovery and a lower incidence of late mitral regurgitation.

Multicenter evaluation of the XT modular coronary stent: clinical and angiographic results.

BACKGROUND: In the past few years, the indications for stent implantation have broadened, along with a larger number of available designs. The Bard XT stent is a new modular stent with an original structure and design. METHODS: To evaluate the new Bard XT stent, we studied its use in a multicenter experience in 163 patients, with a total of 168 lesions and 180 implanted units. RESULTS: Despite the predominance of complex lesions, the procedural success rate was 98%, with only a 2% failure of stent implantation. There was only one death (no-reflow phenomenon in a rescue primary PTCA in a patient in cardiogenic shock) without other major periprocedural complications. Centralized QCA showed a statistically significant increase of MLD (from 0.73 +/- 0.43 mm to 2.71 +/- 0.40 mm, p < 0.0001) and DS reduction (from 73.8 +/- 15.1% pre-treatment to 7.8 +/- 0.4% after stent implantation; p < 0.0001). Aspirin and ticlopidine were routinely administered after the procedure. Thirty-day follow-up reported only one case of subacute stent thrombosis (in the first day), treated with re-PTCA. CONCLUSIONS: In a group of patients with complex lesions, we obtained a high rate of success with a low incidence of complications. The Bard XT stent had a high-performance profile with normalization of vessel diameter and angiographic results similar to the ones obtained with the "slotted tube" stents.

Right pulmonary artery development after modified Blalock-Taussig shunt (MBTS) in infants with pulmonary atresia, VSD and confluent pulmonary arteries.

The ideal palliation for infants with pulmonary atresia, ventricular septal defect and confluent pulmonary arteries should promote normal development of the pulmonary artery branches. In 26 patients who survived a modified Blalock-Taussig shunt (MBTS) in the first year of life, the right pulmonary artery was measured before and after operation by two dimensional (2D) echocardiography. In each patient its size was compared to the normal value for the same body surface area. The patients were divided according to this ratio and according to the real size (mm). Although increased in all cases but two, the size of the right pulmonary artery remained remarkably less than normal in patients with an initially small right pulmonary artery. In view of these results, early palliative enlargement of the right ventricular outflow tract is probably advisable in infants with diminutive pulmonary arteries who do not show adequate pulmonary branch development after MBTS.

[Basal left anterior oblique projection in 2-dimensional echocardiography: its usefulness in defects of the atrioventricular septum]. / La sezione obliqua anteriore sinistra basale in ECO 2D: utilità nei difetti del setto A-V.

The defects of the A-V septum have been recently classified into classes with separate orifices and classes with common orifice on the basis of the presence or not of a tissue tongue which joins the two bridging anterior and posterior leaflets as single differential feature. The diagnostic usefulness of the subxiphoid projection by conventionally called left oblique anterior basal has been evaluated. It indicates in a single plan-section the two bridging leaflets together with the connecting tongue. In 18 cases of defect of A-V septum echo-angiographic correlation was made. The 2D-echo diagnosed in 10 cases a defect of A-V septum with common orifice and in 8 cases a defect of A-V septum with separate orifices. On the contrary the angiocardiography pointed out in 9 cases a defect of A-V septum with separate orifices. Ten of the eighteen patients examined underwent an operation, which has always confirmed the echocardiographical diagnosis; even in the unique case of echo-angio disagreement the diagnosis of 2D-echo was confirmed. Therefore we propose the above-mentioned projection in order to obtain a more accurate non invasive definition in the defects of A-V septum.

Exercise-induced arrhythmias: angiographic correlation and follow-up.

The meaning of exercise-induced arrhythmias was studied in 409 patients who underwent a maximal treadmill test, coronary and ventricular angiography and were followed for 31 +/- 10.6 months. The original population consisted of 1720 patients, of whom 520 were assigned to a group of known or strongly suspected coronary artery disease (Group I) and 1200 were assigned to a group with low likelihood of coronary artery disease (Group II). This division was based on age, history and symptoms. Two hundred and forty-seven (47.5%) patients of group I and 218 (18%) of group II developed ventricular premature beats during the exercise test or the recovery period. The test was positive in 378 (72.6%) patients of group I and in 190 (15.8%) of group II. A complete invasive angiographic study was performed in 233 (44%) patients of group I and 176 (14.6%) of group 2. Exercise-induced ventricular premature beats (VPBs) predicted neither coronary anatomy nor subsequent coronary or surgical events, but a weak relationship was observed with a lower ejection fraction among group I patients. On the other hand, a positive test was predictive of coronary anatomy in both groups and of coronary events in group I. We conclude that, despite a higher prevalence of exercise-induced ventricular premature beats among patients with definite coronary artery disease, an exercise test presenting ventricular premature beats as the only abnormality should not be classified as positive. Patients with such results require further investigation.

[Tetralogy of Fallot. Subcostal approach in bidimensional echocardiography]. / Tetralogia di Fallot. Approccio sottocostale in ecocardiografia bidimensionale.

We have evaluated the diagnostic accuracy of subxyphoid 2-dimensional (2-D) echocardiography in Fallot's tetralogy by employing two planes defined as left anterior oblique (LAO) and right anterior oblique (RAO), similar to the respective angiographic axial projections. Echocardiographic and angiographic findings were compared in 39 patients. The pulmonary branches, the trunk, the infundibulum, the septal defect and the aorta were identified in all cases, the pulmonary valve in 97% and associated defects in 71%. The LAO view was best suited for an overall diagnosis and for the visualization of the left pulmonary branch, of the pulmonary anulus, and of the overriding of the aorta. The RAO proved optimal for the evaluation of the right pulmonary branch, of the infundibulum and of the relationship between ventricular septal defect and adjacent structures. It is concluded that the subxiphoid approach is a valuable technique for the 2-D echocardiographic evaluation of Tetralogy of Fallot.

[Balloon occlusion aortography in the angiographic study of pulmonary atresia with interventricular defect]. / L'aortografia con occlusione nello studio angiografico dell'atresia polmonare con difetto interventricolare.

Balloon aortography is a new technique for the angiographic study of pulmonary atresia with ventricular septal defect. A Swan-Ganz angiographic catheter is employed, whose balloon is inflated to stop blood flow in the descending aorta, thus ensuring the opacification of the pulmonary circulation. By this method we have studied 18 patients. Anatomic details of the pulmonary arterial circulation were obtained in all. No complications occurred. Balloon aortography is a simple and safe technique for the routine study of patients with pulmonary atresia and ventricular septal defect, whereas selective injection in collateral arteries or pulmonary veins, which carries more risk and is more complex, should be adopted only in selected cases.

Comparative accuracy of cross-sectional echocardiography and cineventriculography for left ventricular evaluation after myocardial infarction.

223 patients with a previous myocardial infarction (MI) 29-68 years old, have been studied in a double-blind manner both by 2D-Echocardiography and cineventriculography. 5 cross-sectional views and 2 angiographic projections have been employed in order to assess the presence of aneurysm and the motion of the left ventricle. The left ventricle has been divided into 5 anatomic regions: interventricular septum, anterolateral, posterolateral, apical and inferior walls. By cineangiography an aneurysm was diagnosed in 89 patients (one pseudoaneurysm); by 2D-Echo in 83 patients an aneurysm was diagnosed, whereas in the 6 remaining patients the Echocardiogram was nondiagnostic (specificity 100%, sensitivity 93%). Concerning regional motion characteristics, 997 (89%) of 1115 regions were visualized and 905 (91%) correctly identified according to the angiographic findings. Of 92 discrepancies (9%): 64 were attributed to 2D-Echo (69%) and 28 (31%) were attributed to cineangiography; most of the discrepancies attributed to echo resulted from minor grades of asynergy which caused unresolved disagreements between the Echo and angiography findings. It is concluded that Cross-sectional echocardiography is a valuable tool for the diagnosis of aneurysm of the left ventricle (specificity 100% and sensitivity 93%) and for the study of wall motion characteristics. In cases with generalized abnormality of left ventricle motion, resulting in a picture of congestive cardiomyopathy, 2D-Echo can be a substitute for cineangiography. In all other instances both techniques can provide more complete information on ventricular wall abnormalities.

[Pulmonary stenosis with intact interventricular septum: qualitative and quantitative analysis of the vectorcardiogram (author's transl)]. / Stenosi polmonare a setto interventricolare integro. Analisi qualitativa e quantitativa dell'esame vettorcardiografico.

Eighty-one patients suffering from pulmonary stenosis with intact interventricular septum were divided into two groups according to their age: Group I (greater than 2 years), Group II (less than 2 years). In Group I, patients with RVSP up to 50 mmHg have been included in subgroup A; patients with RVSP from 50 to 90 mmHg in subgroup B, patients with RVSP greater than 90 mmHg in subgroup C. In Group II forms with RVSP less than or equal to 60 mmHg have been considered moderate and forms with RVSP greater than 60 mmHg severe. The rotation and duration of the QRS loop on the various planes, presence of a terminal slowing, the ratios 0,01"/LMSV and 0,02"/LMSV, the LMSV and the RMSV in order to assess the most significant vcgraphic parameters to predict severity of the stenosis have been analysed. A fair correlation has been found between RMSV and RVSP (r = 0,55 in Group I; r = 0,54 in Group II). The AA. conclude that a counterclockwiseloop on the H plane and the presence of a terminal slowing are the most reliable parameters for recognizing the light forms, while the clockwise loop on the H plane and a markedly increased voltage of RMSV indicate more severe stenosis.

[Preliminary study of the pathogenetic mechanisms of pulmonary hypertension due to hypoxia. the role of histamine]. / Studio preliminare sui meccanismi patogenetici dell'ipertensione polmonare da ipossia. Il ruolo dell'istamina.

It has long been supposed that histamine plays an intemediary rôle in pulmonary hypertension due to hypoxia, though no firm evidence has been collected. Lung and aortic pressure and the blood histamine content in the aorta, pulmonary artery, vena cava inferior, and suprahepatic veins were therefore measured in anaesthetised dogs breathing ambient air, and after 5' administration of a gas mixture containing 8% O2. Lung pressure rose significantly and aortic pressure changed only slightly. Histamine values, however, rose significantly in the pulmonary artery and were unchanged in the aorta after the hypoxic stimulus. In addition, concentrations were higher in the vena cava and unchanged in the suprahepatic veins. These results indicate that histamine is released from skeletal muscle and electively taken up by lung tissue during hypoxia. Its rôle is certainly important, but further elucidation must await the performance of other studies using drugs that selectively block its release from the muscle district.

Evaluation by multivariate analysis of changes in systolic time intervals during exercise in the supine and upright positions.

In this study multivariate analysis was adopted to establish how simultaneous changes in heart rate (HR), blood pressure (BP) and work load (W) can affect systolic time intervals (STI). Thus, 13 normal volunteers underwent two consecutive exercise stress tests in the supine and upright position on a bicycle ergometer. By multivariate analysis it was shown that, while in the supine position left ventricular ejection time (LVET) is influenced by HR and W (LVET) = 330.6 - 0.76 HR - 0.41 W, F = 224, P is less than 0.001), in the upright position LVET changes are due only to HR variations (LVET = 309 - 0.88 HR, P is less than 0.001). Pre-ejection period (PEP) in both positions is related to HR and W, but this latter has a non-linear influence (supine: PEP = 110.9 - 0.15 HR -0.34 W + 0.0012 W(2), F = 56.4, P is less than 0.001; upright: PEP = 119 - 0.16 HR - 0.5 W + 0.0025 W(2), F = 86.7, P is less than 0.001). Finally, PEP/LVET ratio is correlated both in the supine and upright position with maximal BP, HR and W; however, the influence of HR and BP is different in the two positions (supine: PEP/LVET = 0.259 + 0.00047 BP + 0.00068 HR - 0.00167 W + 0.000013 W(2), F = 5.68, P is less than 0.01; upright: PEP/LVET = 0.201 + 0.0011 HR - 0.00371 W + 0.00016 W(2), F = 4.79, P is less than 0.01).