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Biomedical subjects

F Lattanzi

Publications and source records attributed to F Lattanzi.

At least 37 records · Page 2Linked to original sources

Normal ultrasonic myocardial reflectivity in hypertensive patients. A tissue characterization study.

Ultrasonic backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content in humans. The integrated backscatter is also increased in hypertrophic cardiomyopathy, whereas it gives normal values in the physiological hypertrophy of elite athletes. We assessed the quantitatively evaluated myocardial reflectivity in 46 mild to moderate, clinically uncomplicated essential hypertensive patients, with echocardiographically assessed normal regional and global left ventricular function, and 22 age- and sex-matched normotensive control subjects. With an echo prototype implemented in our institute, we performed an on-line radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and posterior wall. The integrated values of the radiofrequency signal of myocardial walls were normalized for those of the pericardial interface and expressed as a percent (integrated backscatter index). Hypertensive patients and control subjects differed in mean blood pressure (119 +/- 11 versus 95 +/- 5 mm Hg, p < 0.001) and left ventricular mass index (134 +/- 31 versus 105 +/- 21 g/m2, p < 0.001). However, integrated backscatter index overlapped for both the septum (28 +/- 17% versus 25 +/- 6%, p = NS) and the posterior wall (13 +/- 7% versus 13 +/- 4%, p = NS). In the hypertensive group, there was no detectable correlation between septal integrated backscatter index and either septal thickness (r = -0.26, p = NS) or mean arterial pressure (r = -0.14, p = NS). Hypertensive patients showed a normal pattern of quantitatively assessed ultrasonic backscatter, even in the presence of left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[The ultrasonic characterization of myocardial hypertrophy: new prospects].

The extensive use of ultrasound imaging in cardiology has greatly contributed to expand both its diagnostic possibilities and its utility in the interpretation of physiopathologic mechanisms. Conventional echocardiography is the more specific technique for the diagnosis of myocardial hypertrophy which, in turn, is one of the most important cardiovascular risk factors. The improvement of ultrasound technology may expand the possibility of noninvasive characterization of left ventricular hypertrophy by adding to the already known information about left ventricular mass and function, and that relative to the degree of hypertrophy-related fibrosis. In the present paper the authors reviewed the knowledge about biological and hemodynamic factors which contribute to the development and regression of myocardial hypertrophy. The possible role of new ultrasonic technology in the tissue characterization of myocardial hypertrophy is also discussed.

Cardiomegaly↗

Atrial natriuretic factor in essential hypertension: echocardiographic and humoral correlates.

Aim of this study was to assess the relationship between plasma concentration of atrial natriuretic factor (ANF) and its two-dimensional echocardiographic (left ventricular mass, left atrium diameter) and humoral (plasma renin and aldosterone) variables in essential hypertension (EH). We evaluated 32 patients with uncomplicated mild to moderate EH and 10 controls. They were studied in the supine position after 7 days of constant dietary sodium intake and were off therapy since at least 3 weeks. ANF values overlapped between EH patients and controls (27.8 +/- 11.5 vs. 19.5 +/- 7.4 pg/ml, p = NS). In EH, no significant correlation was found between ANF values and left ventricular mass (r = 0.29), left atrial diameter (r = 0.04), mean arterial blood pressure (r = 0.26), plasma renin activity (r = 0.00), and aldosterone (r = 0.26). In EH, ANF values overlapped between the 15 patients with hypertrophy and the 17 patients with normal ventricular mass: 30.3 +/- 17 vs. 25.6 +/- 10.6 pg/ms (p = NS). We conclude that there is a substantial overlap in plasma ANF values between mild to moderate uncomplicated EH and controls, and left ventricular hypertrophy is not a major independent stimulus to ANF release in EH.

Adult↗

Dipyridamole-echocardiography: clinical usefulness following interventions.

Dipyridamole-echocardiography test response can be expressed not only in a black or white (positive vs negative) code but also, in positive tests, by a gray scale integrating the severity and extent of the dyssynergy as well as the ischemia-free stress time. The recognition of the dyssynergy is important to establish the diagnosis; however, the evaluation of the degree of the induced ischemia, stratified according to spatiotemporal coordinates, is even more important because it accurately predicts the coronary anatomical and functional situation, as well as the prognosis of the individual patient. Furthermore, the "shades of gray" in a positive response have proved useful in assessing the beneficial effects of several interventions: coronary angioplasty; coronary artery bypass surgery; thrombolysis; and medical antianginal therapy. Due to its excellent reproducibility, dipyridamole-echocardiography can play a pivotal role for simple, safe, fast, accurate, and objective assessment of therapeutic interventions, either mechanical or pharmacological, based upon the presence, timing, severity, and extent of dipyridamole-induced dyssynergy.

Angina Pectoris↗

Normal ultrasonic myocardial reflectivity in athletes with increased left ventricular mass. A tissue characterization study.

BACKGROUND: Ultrasonic integrated backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content. The integrated backscatter is also increased in hypertrophic cardiomyopathy, probably because of fiber disarray. The purpose of this study was to investigate myocardial tissue reflectivity in subjects with physiological hypertrophy caused by intense physical training and to assess the relation between the acoustic properties of myocardial tissue and left ventricular wall thickness assessed by conventional two-dimensional echocardiography. METHODS AND RESULTS: Twenty-four young male athletes (14 professional cyclists and 10 weight lifters, all in full agonistic activity) were studied together with 10 normal age-matched controls with sedentary life. By means of a commercially available two-dimensional echocardiograph, standard measurements were obtained according to the recommendations of the American Society of Echocardiography. With a prototype implemented in our Institute, an on-line radiofrequency analysis of ultrasound signals was also performed to obtain quantitative operator-independent measurements of the integrated backscatter of the myocardial walls. The integrated values of the radiofrequency signal were normalized for the pericardial interface and expressed in percent integrated backscatter (%IB). Compared with control subjects, athletes showed greater thickness values of septum (controls, 9 +/- 1; cyclists, 14 +/- 2; weight lifters, 15 +/- 1 mm, mean +/- SD; p less than 0.01) and posterior wall (9 +/- 1, 12 +/- 2, and 12 +/- 1 mm, respectively; p less than 0.01) but similar values of %IB for both septum (23 +/- 4%, 21 +/- 7%, and 23 +/- 8%, p = NS) and posterior wall (10 +/- 2%, 9 +/- 2%, and 11 +/- 2%, p = NS). In athletes, no correlation was found between septal and posterior wall thickness and the corresponding regional myocardial reflectivity (r = 0.23, p = NS and r = 0.01, p = NS, respectively). Furthermore, we compared the quantitative ultrasonic data between two subsets of 10 athletes and 10 patients with hypertrophic cardiomyopathy and similar degrees of septal thickness (16 +/- 1 versus 17 +/- 1 mm, respectively, p = NS). Septal and posterior wall %IB results were significantly higher in patients with hypertrophic cardiomyopathy (53 +/- 13% and 36 +/- 9%, respectively) than in athletes (21 +/- 7% and 10 +/- 3%, respectively; p less than 0.01 for both). CONCLUSIONS: We conclude that 1) endurance athletes show a normal pattern of quantitatively assessed ultrasonic backscatter despite of a marked left ventricular hypertrophy and 2) athletes and patients with hypertrophic cardiomyopathy and similar degrees of myocardial wall thickness can be differentiated on the basis of quantitative analysis of backscattered signal.

Adult↗

Oral vs intravenous dipyridamole echocardiography for detecting coronary artery disease.

The usefulness of the intravenous dipyridamole-echocardiography test (12-lead and two-dimensional [2-D] echo monitoring during dipyridamole infusion) in the diagnosis of coronary artery disease recently has been suggested. However, the intravenous form of dipyridamole is not available for clinical use in some countries and therefore the administration of oral dipyridamole has been employed in combination with echocardiography. In order to evaluate the relative usefulness of the oral (300 mg of pulverized tablets) vs the intravenous (up to 0.84 mg/kg in 10 min) dipyridamole-echocardiography test, we performed the two tests, on different days and in random order, in 28 inhospital patients: 21 had coronary artery disease (seven had one-vessel disease, eight had two-vessel disease, and six had three-vessel disease); seven patients had no significant coronary artery disease. For both tests, the diagnostic end-point was the development of a transient dyssynergy of contraction. Sensitivity was 95 percent for the intravenous and 52 percent for the oral dipyridamole-echocardiography test (p < 0.01); in positive cases, the dyssynergy after the dipyridamole administration appeared at 6.5 +/- 2.5 min for the intravenous and at 27.8 +/- 12.4 min for the oral test (p < 0.01). Specificity was 100 percent for both the intravenous and oral dipyridamole-echocardiography test. One or more extracardiac side effects (headache, gastrointestinal upset, flushing, etc) occurred in 61 percent of the intravenous and 68 percent of the oral tests (p = ns). Nine patients with a positive intravenous and oral dipyridamole-echocardiography test also had a positive exercise-electrocardiography test. A significant correlation between exercise time (ie, the time from onset of exercise and 0.1 m V of ST segment shift) and dipyridamole time (ie, the time from onset of dipyridamole administration and the development of frank dyssynergy) was present for the intravenous (r = 0.6, p < 0.05) but not for the oral test. We conclude that the oral dipyridamole-echocardiography test, in comparison with the intravenous dipyridamole-echocardiography test, has a lower sensitivity and requires a substantially longer imaging time. The dipyridamole time is related to exercise time for intravenous but not for the oral dipyridamole-echocardiography test.

Administration, Oral↗

Stress echocardiography and the human factor: the importance of being expert.

The aim of this study was to evaluate how the diagnostic accuracy of a stress echocardiographic procedure, such as a dipyridamole echocardiography test, depends on the specific experience of the physician interpreting the test. Recordings of 50 consecutive dipyridamole echocardiographic tests were selected for the first part of the study. They were analyzed by 20 experienced echocardiographers with different backgrounds in stress echocardiography: 10 beginners (less than 20 stress studies interpreted with trained staff) and 10 experienced observers (greater than or equal to 100 stress studies performed). Diagnostic accuracy (true positive + true negative/total number of tests) versus the angiographic reference standard (greater than 70% coronary stenosis of at least one major coronary artery) was 62 +/- 6% for beginners and 85 +/- 3% for experienced observers (p less than 0.0001). In the second part of the study, 10 observers (5 beginners and 5 experienced observers) evaluated 2 different sets of 50 dipyridamole echocardiographic test studies before and after the training of the beginners. Before training, the accuracy of beginners was lower than that of experienced observers (61 +/- 7% versus 85 +/- 3%; p less than 0.001). After training, the accuracy gap was closed (83 +/- 3% versus 86 +/- 2%; p = NS). Therefore, interpretation of stress echocardiographic tests by an echocardiographer without specific training severely underestimates the diagnostic potential of this technique. One hundred stress echocardiographic studies are more than adequate to build the individual learning curve and reach the plateau of diagnostic accuracy that the test can yield.

Coronary Angiography↗

Quantitative texture analysis in echocardiography: application to the diagnosis of myocarditis.

Altered myocardial texture associated with inflammatory infiltration or fibrosis of the myocardium has already been described using qualitative and subjective analysis of two-dimensional echocardiograms. The aim of this work is to test whether quantitative analysis of regional image texture in two-dimensional echocardiograms would be an accurate method to identify myocarditis and myocardial fibrosis. A set of 20 two-dimensional studies with endomyocardial biopsy evaluation was examined in 13 patients. Biopsy-proven myocarditis was present in 8 studies; myocarditis and fibrosis in 4; fibrosis in 3; healing/healed myocarditis in 5. A control group of 8 normal subjects was also studied by echocardiography. After quantitative texture analysis of the first order, entropy appeared to consistently differentiate myocarditis from controls. Among second-order parameters, patients affected by myocarditis or fibrosis showed a decreased entropy and higher angular second moment versus controls. We conclude that myocarditis and fibrosis induce similar image texture alterations in ultrasonic images, with increased spatial heterogeneity of the gray level distribution, which can be differentiated from normal structures with digital image analysis techniques.

Adult↗

Quantitative assessment of ultrasonic myocardial reflectivity in hypertrophic cardiomyopathy.

The purpose of this study was to investigate the relation between acoustic properties of the myocardium and magnitude of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy. An on-line radio frequency analysis system was used to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and posterior free wall in 25 patients with hypertrophic cardiomyopathy and 25 normal age-matched control subjects. The integrated values of the radio frequency signal were normalized for the pericardial interface and expressed in percent. Tissue reflectivity was significantly increased in the hypertrophied ventricular septum, as well as in the nonhypertrophied posterior free wall, in patients with hypertrophic cardiomyopathy (58 +/- 15% and 37 +/- 12%, respectively) compared with values in normal subjects (33 +/- 10% and 18 +/- 5%, respectively; p less than 0.001). Furthermore, measurements of reflectivity of the septum or posterior free wall, or both, were beyond 2 SD of normal values in greater than 90% of the patients and were also abnormal in each of the five study patients who had only mild and localized left ventricular hypertrophy. No correlation was identified between myocardial tissue reflectivity and left ventricular wall thickness in the patients with hypertrophic cardiomyopathy (correlation coefficient r = 0.4; p = NS). These findings demonstrate that myocardial reflectivity is abnormal in most patients with hypertrophic cardiomyopathy and is largely independent of the magnitude of left ventricular hypertrophy. Moreover, quantitative analysis of ultrasonic reflectivity can differentiate patients with hypertrophic cardiomyopathy from normal subjects independently of clinical features and conventional echocardiographic measurements.

Adolescent↗

Increased prevalence of ventricular arrhythmias in essential hypertensives with dipyridamole-induced ischemic-like S-T segment changes.

Essential hypertensives are at greater risk for ventricular arrhythmias than normotensive controls. A reduction in coronary flow reserve may be one of the mechanisms underlying this increased prevalence of ventricular dysrhythmias in hypertensives. It has previously been shown that dipyridamole infusion may provoke ischemic-like S-T segment depression in essential hypertensives with angiographically normal coronary arteries and reduced flow reserve. The aim of the present study was to assess whether electrocardiographic positivity (S-T segment depression greater than 0.1 mV from baseline) during dipyridamole testing (12-lead electrocardiogram and two-dimensional echomonitoring, with the infusion of 0.84 mg/kg dipyridamole over 10 min) might identify hypertensives at greater risk for ventricular dysrhythmias. We therefore studied 51 mild-to-moderate essential hypertensives by dipyridamole testing and 48-h Holter monitoring. All patients were off therapy for at least 2 weeks before testing and Holter evaluation. Left ventricular mass (by Penn convention) and ejection fraction (by Teichholtz rule) were evaluated by two-dimensional echocardiography. Lown classes 0-1 were found in 31 patients (Group 1) and Lown classes II-IV in 20 (Group 2). The two groups overlapped for mean blood pressure (121 +/- 9 versus 124 +/- 8 mmHg), left ventricular mass index (120 +/- 27 versus 141 +/- 42 g/m2) and left ventricular ejection fraction (54 +/- 6 versus 52 +/- 6). An electrocardiographically-positive dipyridamole test was found in seven of Group I and 16 of Group II patients (23 versus 80%, P less than 0.01). No patient showed a transient, either regional or global, systolic dysfunction during dipyridamole testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗

Two-dimensional echocardiography in myocardial amyloidosis.

Two-dimensional echocardiography is the best means of identifying early cardiac amyloid infiltration and gauging its subsequent progression. The early asymptomatic phase is characterized on echocardiography by a mild-to-moderate increase in left ventricular and/or right ventricular wall thicknesses. The distinctive combination of low electrocardiography voltage and increase in left ventricular mass on the echocardiogram, both compatible with substantial amyloid infiltration, is valuable in diagnosis and appears to indicate the severity of the disease. Other ancillary but common findings are left atrial dilatation, a small pericardial effusion, thickening of cardiac valves, papillary muscles, and interatrial septum. Finally, there is a peculiar texture of myocardial walls, with highly refractile areas that are typical, although not specific, of myocardial amyloidosis and can also be quantitatively described by digital image analysis techniques. The echocardiographic appearance of amyloidosis can closely mimic several other diseases. Asymmetric hypertrophy of the septum due to amyloid deposition may occur, simulating hypertrophic cardiomyopathy. The granular sparkling of myocardial walls is also found in myocarditis with severe fibrosis, and it is quite common in hypertrophic cardiomyopathy, as well as in other infiltrative diseases of the myocardium. It is not uncommon that the echocardiographic examination represents a turning point in the work-up of the patient, briskly orienting the clinician towards the correct diagnostic pathway. However, the likelihood of the cardiologist-echocardiographer to successfully and prospectively identify myocardial amyloidosis is substantially higher if all the clinical and electrocardiographic information is reviewed at the time of the echocardiographic examination.

Amyloidosis↗

Inhibition of dipyridamole-induced ischemia by antianginal therapy in humans. Correlation with exercise electrocardiography.

BACKGROUND: Dipyridamole echocardiography test (DET: two-dimensional echocardiographic monitoring with dipyridamole infusion up to 0.84 mg/kg in 10 minutes) is a useful tool for the noninvasive diagnosis of coronary artery disease. Aims of the present study were to assess the effects of antianginal drugs on dipyridamole-induced ischemia and to evaluate whether drug-induced changes in DET response may predict variations in exercise tolerance. METHODS AND RESULTS: Fifty-seven patients with angiographically assessed significant coronary artery disease (greater than 70% lumen reduction in at least one major coronary vessel) performed a DET and an exercise electrocardiography test (EET) in random order both off treatment and on antianginal drugs (beta-blockers, calcium antagonists and nitrates, alone or in various combinations). The criterion for DET positivity was a transient dyssynergy of contraction absent or of a lesser degree in the baseline examination. In DET, two parameters were evaluated: the dipyridamole time (i.e., the time from onset of dipyridamole infusion to obvious dyssynergy) and the wall motion score index. DET sensitivity was 91% off therapy and fell to 65% under therapy (p less than 0.01). In the 37 patients who had a positive DET both off and on therapy, the dipyridamole time increased from 6 +/- 3 (off therapy) to 8 +/- 3 minutes (on therapy) (p less than 0.01). The wall motion score index at peak dipyridamole went from 1.38 +/- 0.14 to 1.31 +/- 0.14 (p less than 0.01). EET and DET yielded concordant (positive versus negative) results in 41 of 57 (71%) patients off and in 35 of 57 (61%) on therapy (p = NS). In the subgroup of 38 patients with both positive DET and EET without treatment, the therapy-induced variations in exercise time were significantly correlated with the variations in dipyridamole time (r = 0.5; p less than 0.01), not with variations in wall motion score index (r = 0.3; p = NS). CONCLUSIONS: 1) Antianginal therapy can protect from dipyridamole-induced ischemia and 2) the therapy-induced changes in DET response parallel variations in exercise tolerance and might be useful for the objective, exercise-independent assessment of the therapy efficacy.

Adrenergic beta-Antagonists↗

Lack of correlation between cardiac mass and arteriolar structural changes in mild-to-moderate hypertension.

A morphological restructuring of cardiac and arteriolar tissue is common in hypertension. The parallel evolution of these two processes as a compensatory response to pressure overload is a frequently assumed but unsubstantiated hypothesis. To evaluate this possibility, we have concomitantly measured left ventricular mass (LVM; two-dimensional echo) and minimal forearm vascular resistance (FVR; derived from the ratio of intra-arterial blood pressure: forearm blood flow by venous plethysmography) at maximal postischemic (13 min ischemia + 1 min hand exercise) reactive hyperemia. The study was performed on 29 essential hypertensive patients (15 males, 14 females, aged 50 +/- 10 years) who had not been undergoing treatment for hypertension for at least 15 days at the time of study. Minimum FVR was taken as a hemodynamic index of the integrated arteriolar lumen at the forearm level. LVM index and minimum FVR ranged from normal to clearly altered values. In spite of a wide spread of values, no correlation existed between the individual values of the two variables. Systemic mean blood pressure correlated with minimum FVR and tended to correlate with LVMI. Thus, morphological restructing of cardiac and arteriolar tissue does not seem to evolve in parallel in human hypertension. Pressure overload may contribute to cardiovascular hypertrophy, but other unrelated mechanisms may also underlie the development of cardiac and arteriolar abnormalities of human hypertension.

Arterioles↗

[The diagnostic and prognostic value of echo-dipyridamole in patients with suspected coronary disease: a comparison with the stress test].

The aim of the study was to assess the relative diagnostic and prognostic accuracy of high-dose dipyridamole echocardiography test (DET: 2D-echo monitoring during dipyridamole infusion up to 0.84 mg/kg over 10') vs maximal symptom limited bicycle exercise electrocardiography test (EET) in patients with chest pain addressed to coronary angiography. We initially considered 477 consecutive patients, meeting the following inclusion criteria: 1) history of chest pain; 2) off antianginal therapy; 3) no previous myocardial infarction and/or obvious regional left ventricular dyssynergy of contraction. All patients were submitted to a DET and EET--on different days and in random order--within 1 week of coronary angiography (which was performed independently of test results). DET could not be performed in 32 patients for a poor acoustic window in resting conditions (n = 31) or for asthmatic disease requiring xanthine therapy (n = 1); EET could not be performed in 54 patients for inability to exercise, or resting electrocardiographic abnormalities making the EET interpretable. The overall feasibility was of 445/477 for DET and 423/477 for EET (93 vs 89%, p = ns). Criteria for positivity were: transient regional dyssynergy absent in the baseline examination for DET; ST segment shift greater than .15 m V from baseline for EET. Angiographically assessed coronary artery disease (CAD) was considered present when a luminal reduction greater than or equal to 50% occurred in at least 1 major coronary vessel. There were 135 pts with no significant CAD and 256 with CAD; 137 had single, 70 double, 49 triple and/or left main (15) vessel disease. The specificity was higher in DET vs EET (96 vs 59%, p less than .01). The overall sensitivity of DET was similar to EET (67 vs 69%, p = ns), with no significant differences in the subset with single (56 vs 63%, p = ns), double (74 vs 69%, p = ns) or triple (88 vs 86%, p = ns) vessel disease. Patients were followed-up for 26 +/- 22 (range 1 to 73) months considering only death and myocardial infarction as end-points. A Cox stepwise survival analysis identified the Wall Motion Score Index (an integrated semiquantitative measure of extent and severity of the dyssynergy) at peak dipyridamole as the most powerful prognostic predictor (X2 = 18.5, p less than 0001) of all invasive (number of stenotic coronary vessels, X2 = 5.8, p less than .05) and noninvasive (exercise electrocardiography positivity, p = ns) parameters.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Angiography↗

Dipyridamole echocardiography stress testing in hypertensive patients. Targets and tools.

Arterial hypertension can provoke a reduction in coronary flow reserve through several mechanisms that are not mutually exclusive, namely, coronary artery disease, left ventricular hypertrophy, and microvascular disease. These different targets of arterial hypertension should be explored with different diagnostic markers. The transient dyssynergy detected by two-dimensional echocardiography and evoked during dipyridamole infusion is a marker of coronary disease that is equally reliable in normotensive and hypertensive individuals. On the contrary, dipyridamole-induced ST segment depression is frequently elicited in hypertensive patients when angiographically assessed coronary disease is absent. This ischemiclike electrocardiographic response can be found in echocardiographically assessed left ventricular hypertrophy. However, even when left ventricular mass is normal, dipyridamole-induced ST segment depression is associated with an impaired coronary flow response to pacing, which is consistent with microvascular disease. Whether echocardiographically silent electrocardiographic changes are simply diagnostic noises transmitting a misleading false positive response or a potentially important clinical marker of early myocardial damage remains a pivotal though still unanswered question.

Cardiomegaly↗

Dipyridamole-induced myocardial ischaemia increases ANF release in man.

Atrial natriuretic factor (ANF) release is modulated by several haemodynamic factors, including ventricular and atrial wall stretch. Dipyridamole infusion, which is commonly used as a pharmacological stressor in patients with coronary artery disease, can acutely increase ventricular and atrial pressure via myocardial ischaemia. The aim of this study was to assess whether dipyridamole infusion (up to 0.84 mg kg-1 over 10') can affect ANF release in man. Nineteen patients (13 men, 6 women) with a history of chest pain were studied. Their drug regimen was interrupted and instead they were administered a dipyridamole infusion, combined with two-dimensional echocardiography and 12-lead ECG monitoring. Plasma ANF was measured by RIA while the patients rested, and after dipyridamole infusion. Eight patients had no evidence of myocardial ischaemia, as measured by electrocardiographic and/or echocardiographic criteria, during dipyridamole infusion: among them, ANF values were similar while they were at rest and at peak dipyridamole administration (23.9 +/- 9.5 vs 23.4 +/- 6.9 pg ml-1, P = ns). Eleven patients had dipyridamole-induced transient ischaemia (regional ventricular dyssynergy and/or ST segment depression): among them, ANF values rose significantly at peak dipyridamole administration (31.8 +/- 13.8 vs 65.5 +/- 36.4, P less than 0.01). We conclude that dipyridamole infusion does not increase ANF release in man in the absence of ischaemia. The induction of myocardial ischaemia acutely increases ANF release, probably through a rise in ventricular and atrial wall stress.

Atrial Natriuretic Factor↗

Dipyridamole echocardiography. A new diagnostic window on coronary artery disease.

Dipyridamole echocardiography testing is a highly feasible, inexpensive, and safe diagnostic tool, with excellent specificity and good sensitivity--especially in patients with multivessel disease and/or resting dyssynergy--for the diagnosis of coronary artery disease. The test does not offer an "all or none" binary result but rather a complex stratification of the ischemic response along the coordinates of time and space, accurately identifying the degree of physiological impairment of coronary reserve, the severity and extent of coronary disease, the geographic location of the area at risk, and the prognostic outlook. It offers highly competitive diagnostic information versus more sophisticated, time-consuming, and costly radionuclide techniques; in comparison with other stress echocardiography techniques, it is more feasible than exercise and less invasive and better tolerated than pacing. The electrocardiogram usefully integrates the information provided by the mechanical marker of ischemia during dipyridamole testing. The finding of echocardiographically silent ST segment depression represents a clue to the identification of angiographically normal coronary arteries. On the basis of this evidence, dipyridamole testing with two-dimensional echocardiography and 12-lead electrocardiography can be considered a reasonable choice for the exercise-independent diagnosis of coronary artery disease.

Coronary Disease↗