Normal echocardiographic characteristics of the Sorin Bicarbon bileaflet prosthetic heart valve in the mitral and aortic positions.

Doppler echocardiographic characteristics of normally functioning Sorin Bicarbon prostheses were prospectively assessed in 226 consecutive patients (135 male and 91 female patients, mean age 61 +/- 10 years) with 233 valves in the mitral (n = 67) and aortic (n = 166) positions whose function was considered normal by clinical and echocardiographic evaluation. Patterns of "normal" transprosthetic leakage were assessed with transthoracic echocardiography in all valves and with transesophageal echocardiography in six selected mitral valve prostheses. For the mitral valve prostheses, we found that peak and mean gradient, as well as pressure half-time, were not significantly different in either the 25 or the 31 mm valves (median values from 15 to 10 mm Hg, from 4 to 4 mm Hg, and from 70 to 83 ms; p = Not significant for all). On transthoracic study, 12 patients (17%) with a Sorin Bicarbon valve in the mitral position showed minimal transprosthetic leakage. On transesophageal study, all patients showed a transprosthetic leakage whose spatial distribution had a complex pattern: in planes orthogonal to the leaflet axis, two to four jets arising from the hinge points and converging toward the center of the valve plane could be visualized; in planes parallel to the leaflet axis, there were three jets, the two lateral ones diverging and the central one perpendicular to the valve plane. For the aortic valve prostheses, there was a significant decrease in transprosthetic gradients and an increase in effective orifice areas as prosthesis size increased. Peak and mean gradients decreased from a median value of 25 and 13 mm Hg in the 19 mm valves to 9 and 5 mm Hg in the 29 mm valves, respectively. Effective prosthetic valve area calculated with the continuity equation increased from a median value of 0.97 cm2 for the 19 mm size valves to 3.45 cm2 for the 29 mm size. With analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 40.9, p < 0.0001) better than peak (F = 10.3, p < 0.0001) or mean (F = 8.04, p < 0.0001) gradients alone did. Furthermore, effective prosthetic aortic valve area correlated better than peak and mean gradients with prosthetic size (r = 0.76, r = -0.45, and r = -0.39, respectively). On transthoracic study, 109 patients (66%) showed minimal transprosthetic leakage. These normal values, obtained in a large number of patients with normofunctioning mitral and aortic Sorin Bicarbon valves, may help to identify Sorin Bicarbon prosthesis dysfunction.

Changes in effective aortic valve area during ejection in adults with aortic stenosis.

Measurements of valve orifice area in aortic stenosis are based on the assumption that orifice area remains constant throughout ejection and is independent of transvalvular gradients and flow. Recent studies, however, have suggested that the calculated valve area of calcific aortic stenosis may change in different flow conditions. Therefore, we tested the hypothesis that in vivo effective orifice area of a stenotic aortic valve changes continuously during ejection, which would make a single area measurement a potentially inadequate indicator of the severity of the stenosis. Doppler measurements of flow velocity in the ascending aorta and in the left ventricular outflow tract at peak velocity, at half-peak velocity during acceleration (midacceleration), and at half-peak velocity during deceleration (mid-deceleration) were obtained in 26 patients with aortic stenosis (mean gradient 50 +/- 19 mm Hg and effective aortic orifice are 0.7 +/- 0.3 dcm2) and in 14 normal subjects of similar age and gender, to calculate instantaneous effective aortic orifice area at midacceleration, at peak velocity and at mid-deceleration. In the 26 patients with aortic stenosis, aortic valve area at midacceleration was 84 +/- 15% of valve area at peak velocity (p < 0.0001), and valve area at mid-deceleration was 113 +/- 17% of that measured at peak velocity (p < 0.01). Conversely, in normal subjects, aortic valve area remained constant during ejection and was 97 +/- 5% and 99 +/- 6% of valve area at peak velocity, respectively, at midacceleration and mid-deceleration (p > 0.05). In addition, in patients with aortic stenosis the percentage of change in effective aortic valve area from midacceleration to mid-deceleration varied widely, from -17% to +49% (mean change +26 +/- 14%). There was no relation between percentage of change in effective valve area and mean transaortic gradient (r = 0.05; p = 0.30) or effective valve area at peak velocity (r = -0.11; p = 0.14). Our results indicate that effective aortic valve area continues to change during ejection in patients with aortic stenosis, and that the magnitude of this change is independent of the usual indexes of severity of the stenosis. Conversely, effective aortic valve area remains constant during ejection in normal subjects.

[The methods of using the echocardiogram in outpatients. The role of the cardiologist for more appropriate use of the procedure. The Ligurian Group of the Italian Society of Cardiovascular Echocardiography]. / Modalità di utilizzazione dell'ecocardiogramma in pazienti ambulatoriali. Ruolo del cardiologo per l'appropriatezza della prescrizione. Gruppo Ligure della Società Italiana di Ecografia Cardiovascolare.

Concerns about the increasing medical care costs are causing the medical community to focus its attention on the appropriate of diagnostic tests such as echocardiography. Prerequisite to a better utilization of the limited economic resources assigned to our health care system is an analysis of how, why, and with which results diagnostic tests with a widespread use and relevant cost, like echocardiography, are requested. During the last 2 weeks of September 1994, a transversal, observational study was carried out at 13 hospital echocardiographic laboratories. Ordering physician characteristics, reasons for ordering the test, cardiological diagnostic tests previously performed and their relationship with the test results, were evaluated with a questionnaire completed by the physician who performed the test, in all the out-patients undergoing echocardiogram in that fortnight. Five hundred and sixteen consecutive questionnaires were successfully completed. Fourty-five percent of the echocardiograms were ordered by cardiologists, 35% by general practitioners, 10% by internists, and 10% by other specialists. Hypertension (16.4%) and ischemic heart disease (14.8%) were the most common indications for the test, followed by palpitations or arrhythmias (7.5%), mitral valve prolapse or mitral valve disease (7.3%), chest pain or angina pectoris (6.3%), cardiac murmur (5.5%), dyspnea or heart failure (5.2%), aortic valve disease (5%), prosthetic heart valve evaluation (4.6%), others (27%). Before undergoing the echocardiogram, 433 (84%) patients underwent an electrocardiogram, 242 (47%) a cardiological clinical evaluation, 196 (38%) a chest X-ray, and 191 (37%) had had a previous echocardiogram. The most common echocardiographic diagnosis was normal (29.2%) followed by hypertensive heart disease (16.2%), mitral valve disease (12.3%), aortic valve disease (10.5%), ischemic heart disease (9.3%), cardiomyopathy (4.9%) normal prosthetic heart valve function (4.5%), pericardial effusion (3.8%), others (11.3%). Among the echocardiograms ordered by cardiologists, 21.8% were normal in comparison with 35.4% of those ordered by general practitioners (p < 0.004), 35.3% of those ordered by internists (p = 0.04), 35.3% of those ordered by other specialists (p = 0.04). Among the 284 patients whose echocardiograms were not requested by a cardiologist, only 215 (76%) had undergone an electrocardiogram and only 68 (24%) a clinical evaluation by a cardiologist. In these patients, the frequency of normal echocardiograms was not influenced by having undergone a previous electrocardiogram or a chest X-ray. Conversely, patients in whom the echocardiogram was ordered after a cardiology consult showed a significant lower frequency of normal results compared to patients not evaluated by a cardiologist (23% vs 39%; p < 0.05). More than 50% of the echocardiograms performed in out-patients are ordered by physicians who are not cardiologists. Among these echocardiograms, about 1 out of 3 results normal. This finding suggests an improper use of echocardiogram as a screening tool by non-cardiologists in out-patients. A preceding clinical evaluation by a cardiologist, but not an electrocardiogram or a chest X-ray alone, may determine a more appropriate use of the test being associated with a reduced frequency of normal results.

[Doppler echocardiographic evaluation of the new mechanical bileaflet Sorin Bicarbon valve prosthesis compared with St. Jude Medical]. / Valutazione eco-Doppler della nuova protesi valvolare meccanica ad emidischi Sorin Bicarbon e confronto con la St. Jude Medical.

BACKGROUND: Despite the Bicarbon valve has been marketed for more than two years, no systematic Doppler evaluation of its normal functioning has yet been published. Therefore, the aims of this study were to establish the normal flow characteristics for the Bicarbon bileaflet prosthetic heart valve and to compare them with those obtained from the St. Jude Medical valve prosthesis. METHODS: Doppler echocardiographic characteristics of normally functioning Bicarbon prostheses were prospectively assessed in 76 consecutive patients (44 males and 32 females, mean age 60 +/- 10 years) with 79 valves in mitral (n = 29) and aortic (n = 50) position whose function was considered normal by clinical and echocardiographic evaluation. In addition, Doppler characteristics of the Bicarbon valves in aortic position were compared to those of 27 normal functioning St. Jude Medical implanted during the same period. RESULTS: For the mitral valve prostheses, we found non significant difference among prosthesis sizes in terms of transprosthetic gradients or pressure half time. Peak and mean gradients were similar in the 27-mm and 31-mm size valves (from 11 +/- 4 to 11 +/- 2 mm Hg and from 5 +/- 2 to 5 +/- 1 mm Hg, respectively; p = NS for both). Similarly, the pressure half time was similar in the 27-mm and in the 31-mm size valve (85 +/- 16 and 76 +/- 13 msec; p = NS). Conversely, for the aortic valve prostheses, there was a significant decrease in transprosthetic gradients and an increase in effective orifice areas as prosthesis size increased. Mean gradient was 13 +/- 1 mm Hg in 19-mm size valves, and it decreased to 6 +/- 2 mm Hg in the 29-mm size. Effective prosthetic valve area calculated using the continuity equation, ranged between 1.0 +/- 0.3 cm2 for 19-mm size valves to 3.5 +/- 0.7 cm2 for 29-mm size. With analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 23.3; p < 0.0001) better than peak (F = 3.2; p = 0.017) or mean (F = 4.19; p = 0.0035) gradients alone did. Furthermore, effective prosthetic aortic valve area correlated better than peak and mean gradients with prosthetic size (r = 0.87, r = -0.58 and r = -0.57; respectively). In addition, peak and mean transprosthetic gradients and effective prosthetic aortic valve areas did not show any statistically significant difference between the Bicarbon and the St. Jude Medical valves in aortic position, either in 19 and 21 mm (25 +/- 8 mm Hg, 13 +/- 4 mm Hg, 1.3 +/- 0.3 cm2 and 32 +/- 11 mm Hg, 17 +/- 6 mm Hg, 1.2 +/- 0.4 cm2, respectively; p = NS), or in 23 and 25 mm (21 +/- 8 mm Hg, 11 +/- 4 mm Hg, 2.1 +/- 0.5 cm2 and 24 +/- 11 mm Hg, 12 +/- 5 mm Hg, 1.8 +/- 0.4 cm2, respectively; p = NS) or in 27 and 29 mm (12 +/- 2 mm Hg, 7 +/- 1 mm Hg, 2.8 +/- 0.9 cm2 and 16 +/- 5 mm Hg, 7 +/- 2 mm Hg, 2.6 +/- 0.4 cm2, respectively; p = NS). CONCLUSIONS: This study suggest that the Bicarbon valve prosthesis offers relatively little resistance to forward flow except at a small anulus diameter. Furthermore, these is no statistically significant difference between the Bicarbon and the St. Jude Medical in aortic position with regard to early hemodynamic performances.

Doppler haemodynamic assessment of clinically and echocardiographically normal mitral and aortic Allcarbon valve prostheses. Valve Prostheses Ligurian Cooperative Doppler Study.

Doppler echocardiographic characteristics of normally functioning Allcarbon prostheses were studied in 149 consecutive patients with 157 valves in the mitral (n = 73) and aortic (n = 84) positions whose function was considered normal by clinical and echocardiographic evaluation. In the mitral position, the mean gradient and the effective mitral orifice area were not significantly different in either the 25-mm or the 31-mm size valves (from 5 +/- 1 to 4 +/- 1 mmHg and from 2.2 +/- 0.6 to 2.8 +/- 0.9 cm2, respectively; P = ns for both). Conversely, peak gradient was significantly and inversely correlated to actual orifice area (r = -0.70; P < 0.0006), decreasing from 15 +/- 3 mmHg in the 25-mm size valve to 9 +/- 1 mmHg in the 31-mm size. In the aortic position, the mean gradient was 29 +/- 8 mmHg in the 19-mm size valve; it decreased to 8 +/- 2 mmHg in the 29-mm size. Effective prosthetic aortic valve area, calculated using the continuity equation, ranged between 0.9 +/- 0.1 cm2 for the 19-mm size valve to 4.1 +/- 0.7 cm2 for the 29-mm size. By analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 25.3; P < 0.0001) better than peak (F = 5.34; P = 0.012) or mean (F = 4.34; P = 0.0052) gradients alone, and it correlated better with actual orifice area (r = 0.89, r = -0.70 and r = -0.65, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Infective right atrial thrombus: a rare complication of total parenteral nutrition in an adult.

We describe a case of an infective right atrial thrombus, following total parenteral nutrition, in a 21-year-old woman undergoing a surgical procedure for long-standing chronic ulcerative colitis. She presented with high temperature and the illness did not respond to antibiotic therapy. A 2-dimensional echocardiogram showed a mobile right atrial mass that at surgery was identified as a thrombus. Thrombus cultures grew coagulase-negative Staphylococcus aureus.

[Age-induced changes in the cardiovascular system in normal subjects]. / Modificazioni del sistema cardiovascolare indotte dall'età in soggetti normali.

To assess the effect of age on cardiac structure and function, we performed echocardiograms on 104 physically active, normal, community-dwelling volunteers (68 men and 36 women), ranging in age from 18 to 84 years and having no evidence of hypertension or cardiovascular disease. With advancing adult aging, the following were observed: a decrease in aortic compliance (r = 0.42); an increase in systolic (r = 0.61), diastolic (r = 0.24), pulse (r = 0.60) and mean (r = 0.48) arterial pressure; and a modest enlargement of aortic root (r = 0.47) and left atrial dimension (r = 0.30) were observed. Left ventricular end-diastolic volume (r = 0.25), wall thickness (r = 0.30) and mass (r = 0.37) also increased with aging, while left ventricular end-systolic volume was not age-related. Furthermore, a stepwise multivariate linear model identified the decrease in arterial compliance (R2 = 0.06; p < 0.02) and the increase in left ventricular stroke work (R2 = 0.38; p < 0.0001) as the only variables independently related to the increase in left ventricular mass that occurs with advancing age. Regarding left ventricular systolic function, aging was also related to an increase in left ventricular stroke work (r = 0.40) and ejection time (r = 0.44), while pump function, (measured as ejection fraction and cardiac index at rest), and contractility (measured by load independent end-systolic indexes) were unaffected by aging. Conversely, pulsed Doppler analysis of mitral inflow showed a significant age-related decline in the peak early filling velocity (r = -0.45) and in the ratio of early and late diastolic filling velocity (r = -0.66), while peak late diastolic flow velocity (r = 0.50), diastolic pressure half time (r = 0.34) and duration of isovolumic relaxation (r = 0.56) increased significantly with age.

[Changes in modalities of left ventricular filling associated with aging in normal subjects: secondary to increase in blood pressure and left ventricular mass?]. / Alterazioni delle modalità di riempimento del ventricolo sinistro associate all'aumento dell'età in soggetti normali: secondarie all'aumento della pressione arteriosa e della massa del ventricolo sinistro?

The mechanisms by which aging alters the pattern of left ventricular diastolic filling are still uncertain. To gain more insight into this tissue, the independent contributions of age, sex, heart rate, arterial blood pressure and left ventricular mass (as well as various indexes of left ventricular morphology and function) to left ventricular diastolic filling abnormalities, were investigated by echocardiography in 81 normal subjects (18 to 84 years of age, mean 50), carefully screened to avoid the confounding effects of coronary artery disease and systemic hypertension. With advancing adult age, we found a significant increase in: body mass index (r = 0.25; p less than 0.02), systolic (r = 0.58; p less than 0.0001), pulse (r = 0.61; p less than 0.0001) and mean (r = 0.40; p less than 0.0001) arterial blood pressure; left ventricular wall thickness (r = 0.30; p less than 0.006); left ventricular mass (r = 0.32; p less than 0.004); left ventricular end-diastolic volume (r = 0.24; p less than 0.03); and peak systolic wall stress (r = 0.22; p less than 0.04). Pulsed Doppler analysis of mitral inflow showed a significant age-related decline in the peak early filling velocity (r = -0.51; p less than 0.001), and in the ratio of early and late diastolic filling velocity (r = -0.65; p less than 0.0001). Conversely, duration of isovolumic relaxation (r = 0.77; p less than 0.0001), peak late diastolic flow velocity (r = 0.39; p less than 0.001), and diastolic pressure half time (r = 0.34; p less than 0.01) increased significantly with age. "Stepwise" multivariate linear regression analyses showed that the ratio of early to late diastolic peak filling velocity was independently related only with age (R2 = 0.56; p less than 0.0001) while the isovolumic relaxation time was independently related with age (R2 = 0.48; p less than 0.0001) and duration of cardiac cycle (R2 = 0.06; p less than 0.008). Age-related changes in body mass index, blood pressure, peak meridional wall stress and left ventricular mass index did not show any independent relationship to Doppler parameters of left ventricular filling or duration of isovolumic relaxation. The results of the present study suggest that the effect of age on left ventricular filling modalities and duration of isovolumic relaxation are independent of age-related changes in blood pressure, left ventricular mass, morphology and systolic function.

Concentric left ventricular wall thickening in a patient with primary hypothyroidism. Response to gradual thyroxine replacement.

Asymmetric septal thickening has been described in patients with overt myxedema, but descriptions of concentric left ventricular wall thickening in such patients are rare. Echocardiographic detection of thickened left ventricular and interventricular walls, without pericardial effusion or any other sign of cardiac involvement, in a patient with overt myxedema and primary hypothyroidism, is reported. Furthermore, this is the first case in which the timing and the extent of the response of such abnormalities to L-thyroxine replacement therapy have been serially evaluated.

Frequency, characteristics and significance of supraventricular tachyarrhythmias detected by 24-hour electrocardiographic recording in the late hospital phase of acute myocardial infarction.

The incidence, characteristics and clinical significance of supraventricular tachyarrhythmias occurring in the late hospital phase of acute myocardial infarction (AMI) were assessed in 209 consecutive patients. Arrhythmias were quantified by 24-hour electrocardiographic recording 16 +/- 3 days after AMI, and were classified according to the degree of complexity in 5 classes. Class 0 = less than 5 premature beats/hr; class 1 = between 5 and 100/hr; class 2 = greater than 100/hr or repetitive premature beats; class 3 = atrial-junctional tachycardia; class 4 = atrial flutter-fibrillation. Supraventricular tachyarrhythmias classes 1 to 2 always occurred in the absence of symptoms in 86 patients (41%); supraventricular tachyarrhythmias classes 3 to 4 (paroxysmal, self-limiting, brief) occurred in 27 patients (13%), symptomatically in 6. The presence of supraventricular tachyarrhythmias classes 2 to 3 was related to age over 55 years and complex ventricular tachyarrhythmias (greater than 20 premature beats/hr, ventricular tachycardia) (both p less than 0.05). Increasing complexity of supraventricular tachyarrhythmias was significantly associated with presence and entity of cardiac enlargement and left ventricular dysfunction (both p less than 0.01). Patients with class 4 showed the most severe cardiac deterioration. During the 2 years after AMI, patients with classes 2, 3 and 4 had a higher incidence of acute pulmonary edema, New York Heart Association functional classes III to IV for congestive heart failure (both p less than 0.005) and a greater need of digitalis and diuretics (p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical course and prognosis of hypertrophic cardiomyopathy in an outpatient population.

Hypertrophic cardiomyopathy has been investigated mainly at referral institutions. Thus, the clinical history of the disease that emerges from published studies could be influenced by a bias in patient selection. In the present study, we compared the clinical features of an outpatient population of 25 patients who had hypertrophic cardiomyopathy with those reported in 78 studies published during the past five years. In the 25 study patients, age, sex, and the extent of left ventricular hypertrophy, as well as the prevalence of diastolic filling abnormalities, subaortic obstruction, and ventricular arrhythmias, were similar to those in patients described in the literature. Cardiac symptoms, however, were much less severe in the study patients. Eighteen patients (72 percent) were asymptomatic, six (24 percent) had mild symptoms, and only one (4 percent) had moderate-to-severe symptoms. Of 24 patients followed for a mean period of 4.4 years (range, 2.9 to 5.7), none died or had clinical deterioration. Of 3404 patients described in the 78 studies we reviewed, 2483 (73 percent) came from only two referral institutions. Of the 1721 patients in whom severity of symptoms was reported, 757 (44 percent) had moderate-to-severe symptoms. However, 727 (96 percent) of these patients were studied at one of the same two referral institutions. We conclude that the natural history of hypertrophic cardiomyopathy may be more benign than can be inferred from published reports.

[Pacemaker malfunctioning caused by subcutaneous emphysema]. / Malfunzionamento di pace-maker da enfisema sottocutaneo.

We report a case of early pace-maker malfunction associated with a collection of air which separates the anodal contact plate of a unipolar permanent generator from the underlying tissues. The air pocket resulted from a complication of the percutaneous technique used to introduce the electrocatheter through the subclavian vein. Loss of capture was attributed to a critical increase in impedance to current flow in the pacing system. The malfunction was corrected by simple non-invasive procedures at the patient's bedside. Air pocket can cause the loss of stimulation of the pace-maker.

The relation between supraventricular tachyarrhythmias and left ventricular dysfunction after acute myocardial infarction.

The clinical characteristics of supraventricular tachyarrhythmias (SVTA) and their relation to left ventricular dysfunction were assessed in 208 consecutive patients with recent myocardial infarction. Arrhythmias were quantified on hospital discharge by 24 hour electrocardiographic recording. All the variables were evaluated between the second and the fourth week after infarction. SVTA occurred in 113 (54%) patients: Supraventricular premature beats (SVPB) in 49 (24%), frequent or repetitive SVPB in 37 (18%), atrial or junctional tachycardia in 23 (11%), atrial flutter or fibrillation in 4 (2%). Most of these arrhythmias occurred in the absence of symptoms, and the most complex forms were always selflimiting. No relation was found among the presence of different forms of SVTA and sex, coronary risk factors, previous history of ischemic heart disease, type or site of acute myocardial infarction, NYHA functional class. Age, left atrial dimension (LAD), cardio-thoracic ratio (CTR) and left ventricular ejection fraction (LVEF) at rest differed significantly among three groups of patients: those without SVTA, those with SVPB less than 100 per hour and those with frequent-repetitive SVPB or atrial-junctional tachycardia. The more SVTA complexity, the worse LAD, CTR, LVEF and the higher the age. Multivariate discriminant analysis showed that CTR was directly and LVEF inversely related to the occurrence of SVPB less than 100 per hour, while the presence of frequent-repetitive SVPB or supraventricular tachycardia was closely related to increasing age, LAD, CTR and decreasing LVEF. Patients with atrial fibrillation always showed the worst values of LAD, CTR, LVEF and age. The results of the present study show that different types of SVTA occurring at discharge from hospital after myocardial infarction are clinically benign, but always suggestive of different degrees of left ventricular dysfunction.

[Efficacy of propafenone in the treatment of ventricular hyperkinetic arrhythmias in subjects with a history of myocardial infarction]. / Efficacia del propafenone nel trattamento delle aritmie ipercinetiche ventricolari in soggetti con pregresso infarto miocardico.

A placebo-controlled single-blind study was performed to evaluate the efficacy of oral propafenone on stable potentially malignant ventricular tachyarrhythmias in 13 patients who had suffered a myocardial infarction two months or longer before the trial. All patients exhibited at a 24 hour Holter monitoring a minimum mean frequency of 10 ventricular premature depolarizations (VPDs) per hour and repetitive VPDs. Ventricular tachyarrhythmias characterization was obtained by means of multiple Holter monitorings and exercise stress testings. Propafenone was considered as effective when a well-defined quantitative and qualitative reduction of ventricular tachyarrhythmias was reached. After an initial placebo phase, patients received propafenone 450 mg or 900 mg daily. Acute effectiveness of propafenone was proved in 8 on 13 patients (62%) who showed a significative reduction of VPDs (89%, p less than 0.02) and a suppression of the most complex forms of ventricular tachyarrhythmic events. The efficacy of propafenone was confirmed, three months later, in each patient, side effects were infrequent, minimal and of no clinical consequence. Oral propafenone can be considered as an effective drug for reducing the level of potentially malignant ventricular tachyarrhythmias in patients with previous myocardial infarction.

Clinical significance of supraventricular tachyarrhythmias after acute myocardial infarction.

160 survivors of acute myocardial infarction (AMI) were evaluated to assess the clinical significance of supraventricular tachyarrhythmias (SVTA) occurring at discharge from the hospital after the acute event. All the variables considered for the study were estimated before hospital discharge; arrhythmias were quantified with a 24 h Holter ECG monitoring system. SVTA occurred in 88 patients (55%). Single or repetitive supraventricular premature beats were found in 65 (41%), paroxysmal atrial or junctional tachycardias in 20 (12%), bouts of atrial flutter or fibrillation in 3 (2%). Bivariate statistical analysis showed no relationship between sex, previous cardiovascular history, type, and location of AMI and SVTA occurrence. A close positive relationship was found between age, left atrial dimension (LAD), cardio-thoracic ratio (CTR) and SVTA occurrence; an inverse relationship was found for left ventricular ejection fraction (LVEF). The presence of SVTA appeared significantly related to age above 55 years, to LAD greater than 40 mm, to LVEF less than 45%, to serum creatine kinase peak levels over 1400 U l-1 and to CTR over 0.49. Multivariate statistical analysis showed that five variables are important in discriminating patients suffering from SVTA: age, LAD, LVEF, left ventricular fractional shortening, and CTR. SVTA occurring at discharge from hospital after AMI are indicative of impaired left ventricular pump function.