The flow-function relationship in patients with chronic coronary artery disease and reduced regional function: a Doppler transesophageal and bidimensional transthoracic echocardiography study.

BACKGROUND: Infra-low dose dipyridamole allows one to selectively explore myocardial viability. Transesophageal echocardiography Doppler measurement of left anterior descending coronary artery flow at baseline and following dipyridamole is an efficient tool to assess coronary flow response. Aim of this study was to determine the flow-function relationship during coronary vasodilatory stress in patients with coronary artery disease and baseline dysfunction. METHODS AND RESULTS: Twelve patients with resting dyssynergies and 6 controls underwent assessment of regional function and of left anterior descending blood flow velocity. Flow and function were evaluated at rest and following infra-low dose dipyridamole (0.28 mg/Kg over 4 min). Controls showed a normal function at rest and after dipyridamole. Six patients ('Responders') with resting dyssynergies showed an improvement in segments of left anterior descending artery territory, whereas the other six ones ('Non-responders') showed no functional change. Controls and 'Responders' had similar values of resting peak diastolic left anterior descending artery flow velocity both at rest and after dipyridamole, whereas 'Non-responders' showed a blunted flow response to dipyridamole. CONCLUSION: Myocardial segments with a resting dysfunction and a contractile reserve more often exhibit a residual flow response, whereas segments with fixed pattern show a flat flow response during coronary vasodilator stress.

Preoperative assessment of coronary artery disease in aortic stenosis: a dipyridamole echocardiographic study.

BACKGROUND: The aim of this study was to establish the feasibility, safety, and diagnostic accuracy of the dipyridamole echocardiography test in patients with severe aortic valve stenosis for noninvasive detection of coexisting coronary artery disease. METHODS: The high-dose dipyridamole echocardiography test was performed in 52 patients with severe aortic stenosis; all patients also underwent coronary angiography, independent of test results, before cardiac operation. RESULTS: The dipyridamole echocardiography test was completed without major complications. One patient had transient atrial fibrillation that was reversed by aminophylline. Thirty-one patients (60%) had a negative test result; all had normal coronary arteries. Ten of the 21 patients (48%) with a positive test result had coexisting coronary artery disease. The positive predictive value of the dipyridamole echocardiography test for detection of coronary disease in patients with severe aortic stenosis was 48%. The negative predictive value was 100%. The sensitivity was 100% and the specificity was 74%. CONCLUSIONS: Dipyridamole echocardiography is a safe and feasible tool in patients with severe aortic stenosis eligible for a cardiac operation. A negative test result reliably rules out a significant stenosis, whereas a positive one is much less accurate in predicting coronary artery disease.

Ambulatory follow-up of aortic dissection: comparison between computed tomography and biplane transesophageal echocardiography.

UNLABELLED: Aim of the study was to assess the relative usefulness of transesophageal echocardiography (TEE) and X-ray computed tomography (CT) in the follow-up of patients who survived an aortic dissection. MATERIALS AND METHODS: We evaluated 44 patients (age = 57 +/- 12 years) with treated aortic dissection: 14 had a De Bakey type I, 20 a type II and 1 patient a type III dissection treated surgically: 1 patient had a type I, 1 a type II and 7 a type III dissection treated medically. All entered an outpatient follow-up program with serial evaluations at 1, 6 and 12 months after initial diagnosis by dual noninvasive imaging protocol. A contrast-enhanced CT scan and a TEE with biplane probe were performed on the same day and in random order. RESULTS: A total of 252 evaluations with both CT and TEE were considered. A completely normal study was found in 45 TEE and 48 CT evaluations. The following abnormal findings could be documented by one or both techniques: thrombus in the false lumen (TEE: n = 48; CT: n = 45 evaluations); intimal flap (TEE and CT: n = 68); aortic dilatation (TEE and CT: n = 15); pericardial effusion (TEE and CT: n = 3); aortic pseudoaneurysm (TEE: n = 2; CT: n = 3); isthmic coarctation (TEE and CT: n = 1). Regarding the presence or absence of these abnormalities, which are within the diagnostic domain of both imaging techniques, the results were fully concordant in 245 studies, and discordant in 7, with an overall agreement of 97%. In addition, some abnormal findings could be detected by TEE only: aortic insufficiency (n = 36); intimal tear (n = 25); spontaneous echocontrast effect in the false lumen (n = 39 evaluations). Other abnormal findings could be detected by CT only: a pleural effusion in 4, a truncus anonymous dissection in 1, a pseudoaneurysm due to suture dehiscence of the distal anastomosis of the ascending aorta in 1 evaluation (which yielded ambiguous results by TEE, with turbulent flow departing from the graft). CONCLUSION: Both CT and TEE are atraumatic, safe and accurate techniques for serial follow-up imaging of patients treated for aortic dissection. Information provided by CT is largely redundant, rather than additive, to that provided by TEE. The latter should be probably preferred for shorter imaging time, accuracy and convenience, although CT might still play a role in selected cases of ambiguous TEE results.

Mechanisms of regional ischaemic changes during dipyridamole echocardiography in patients with severe aortic valve stenosis and normal coronary arteries.

OBJECTIVE: Vasodilator stress echocardiography can cause myocardial ischaemia in patients with severe aortic valve stenosis and angiographically normal coronary arteries. The aim of the study was to determine the mechanism of ischaemia in this clinical model. METHODS: The study group comprised patients with severe aortic valve stenosis and normal coronary arteries: 25 patients (17 males, eight females; age 63 (SD 11) years) underwent a high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography test both before (2-4 d) and after (10-15 d) aortic valve replacement. Mean aortic pressure gradient was 96 (15) mm Hg, with a left ventricular mass index of 228 (49) g/m2. The dipyridamole echocardiography test was well tolerated and interpretable in all patients. RESULTS: Dipyridamole infusion induced chest pain in seven patients before and in no patient after surgery (28 v 0%, P < 0.01), ST segment depression in 12 patients before and two after surgery (48 v 8%, P < 0.01), and a transient regional dyssynergy in 10 patients before and two after surgery (40 v 8%, P < 0.01). In the preoperative evaluation, patients with an echocardiographically positive dipyridamole echocardiography test were comparable with patients with negative test as far as left ventricular mass index [240 (67) v 230 (64) g/m2, NS] and mean aortic pressure gradient [95 (22) v 92 (21) mm Hg, NS] were concerned. When compared to the preoperative assessment, the resting echo assessment in the postoperative evaluation showed unchanged values of left ventricular mass index [pre 228 (49) g/m2 v post 220 (36) g/m2, NS], but markedly decreased values of mean aortic gradient [pre 95 (15) mm Hg v post 22 (5) mm Hg, P < 0.01] and left ventricular wall stress index [pre 134 (30) g/cm2 v post 89 (19) g/cm2]. CONCLUSIONS: Dipyridamole echocardiography is a suitable clinical technique for assessing the ischaemic vulnerability of the left ventricle in severe aortic valve stenosis with angiographically normal coronary arteries. The frequent disappearance of the ischaemic response early after aortic valve replacement suggests that haemodynamic factors such as compressive diastolic wall stress or afterload reduction are important components of myocardial ischaemic vulnerability under these circumstances.

Cardiac cycle-dependent gray-level variation is not distorted by abnormal septal motion after cardiac surgery: a transesophageal videodensitometric study in humans.

Variation in cyclic (systolic-to-diastolic) echodensity has been demonstrated to be a reliable index of preserved myocardial function. Paradoxic septal motion can be observed frequently after cardiac surgery in the absence of any functional impairment. The aim of the study was to evaluate whether regional cycle-dependent gray-level variation in the septum is affected by abnormal septal motion after cardiac surgery. Ten patients undergoing cardiac surgery for coronary artery bypass grafting were evaluated by continuous transesophageal echocardiographic monitoring from the transgastric approach, both before and after surgery. In each patient septal motion was assessed qualitatively as normal or paradoxic. Images were digitized off-line and cyclic gray-level variation was measured in each patient by means of dedicated software. By selection, all patients exhibited normal septal motion and thickening at baseline. After surgery, five patients showed a paradoxic septal motion (group I), whereas in the remaining five patients (group II) septal motion remained normal. Percent area change, measured with the floating center-of-mass reference system, was similar in the two groups both before (I = 42% +/- 7% versus II = 44% +/- 13%; difference not significant) and after surgery (I = 39% +/- 8% versus II = 40% +/- 1%; difference not significant). Cyclic gray-level variation was also similar in the two groups, both at baseline (group I = 61% +/- 16% versus group II = 68% +/- 18%; difference not significant) and after surgery (50% +/- 13% versus 57% +/- 16%; difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic value of the dipyridamole echocardiography test performed early after aortocoronary bypass surgery.

It has been demonstrated that high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography stress testing is feasible even in the first few hours after coronary artery bypass graft surgery and can be used to assess the beneficial physiological effects of coronary revascularization as well as graft patency. The aim of this study was to assess the role of dipyridamole echocardiography testing performed shortly after myocardial revascularization in the stratification of prognosis during follow-up. We studied 49 consecutive patients (45 males and 4 females; mean age 56 +/- 8 years) referred to our institute for elective myocardial revascularization. Six patients had single, 14 double, and 29 triple vessel disease. Forty-two left internal mammary artery grafts, 16 sequential venous grafts, and 45 single venous grafts were performed. All patients were submitted to dipyridamole echocardiography testing before (range 1-3 days) and shortly after (range 5-7 days) myocardial revascularization, always with the patients off antianginal medication. An arbitrary wall-motion score grading from 0 to 3 (normal, hypokinesia, akinesia, and dyskinesia) was applied to the seven regions into which the left ventricle was divided. Before surgery 48 patients showed wall-motion abnormalities during the test (47 patients also presented ECG changes). Angina occurred in 48 patients. One patient had ischemic ECG changes and angina. The mean wall-motion score was 3.11 per patient before and 6.5 per patient after the test (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)