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Objective: Most women with a pregnancy complicated by preeclampsia have either hypertension or a disorder with a thrombophilic phenotype or both of these. In this study we evaluated whether hemodynamic variables and volume homeostasis in a subgroup of normotensive women with a history of preeclampsia with normal clotting function (defined as the symptom-free subgroup) were comparable with those in a healthy parous control group., Study Design: In a group of 58 subjects with a history of preeclampsia and a group of 11 healthy parous control subjects we measured the following variables > or = 5 months post partum at day 5 +/- 2 of the menstrual cycle: body weight and length, mean arterial pressure, heart rate, cardiac output, plasma volume, glomerular filtration rate, effective renal plasma flow, and plasma concentrations of volume regulatory hormones, clotting factors, antiphospholipid antibodies, and homocysteine before and after a methionine load. From the measured data we calculated body mass index, body surface area, cardiac index, left ventricular work, total peripheral and renal vascular resistances, effective renal blood flow, and renal filtration fraction., Results: Among women with a history of preeclampsia 26 were normotensive with thrombophilia (45%), 14 had hypertension (24%), and 18 were normotensive without thrombophilia (31%). These last symptom-free subjects with a history of preeclampsia were more obese than were control subjects. They also had higher cardiac output and left ventricular work and a lower plasma volume than the healthy parous control subjects. Thus they resemble the second subgroup of subjects (subjects with hypertension and a history of preeclampsia) rather than the control subjects. The hemodynamic and renal functions in the subgroup of subjects with a history of preeclampsia with normotension and thrombophilia were similar to those in healthy parous control subjects., Conclusion: On the basis of this study we conclude that hemodynamic parameters and volume homeostasis in the symptom-free subgroup of women with a history of preeclampsia are different from those in healthy parous control subjects. Hemodynamic parameters and volume homeostasis in this subgroup resemble those of women with hypertension and a history of preeclampsia. We therefore propose the classification of these symptom-free subjects with a history of preeclampsia as having "latent" hypertension.

Objectives: The study assessed the value of the electrocardiogram (ECG) as predictor of the left anterior descending coronary artery (LAD) occlusion site in relation to the first septal perforator (S1) and/or the first diagonal branch (D1) in patients with acute anterior myocardial infarction (AMI)., Background: In anterior AMI, determination of the exact site of LAD occlusion is important because the more proximal the occlusion the less favorable the prognosis., Methods: One hundred patients with a first anterior AMI were included. The ECG showing the most pronounced ST-segment deviation before initiation of reperfusion therapy was evaluated and correlated with the exact LAD occlusion site as determined by coronary angiography., Results: ST-elevation in lead aVR (ST elevation(aVR)), complete right bundle branch block, ST-depression in lead V5 (ST depression(V5)) and ST elevation(V1) > 2.5 mm strongly predicted LAD occlusion proximal to S1, whereas abnormal Q-waves in V4-6 were associated with occlusion distal to S1 (p = 0.000, p = 0.004, p = 0.009, p = 0.011 and p = 0.031 to 0.005, respectively). Abnormal Q-wave in lead aVL was associated with occlusion proximal to D1, whereas ST depression(aVL) was suggestive of occlusion distal to D1 (p = 0.002 and p = 0.022, respectively). For both the S1 and D1, inferior ST depression > or = 1.0 mm strongly predicted proximal LAD occlusion, whereas absence of inferior ST depression predicted distal occlusion (p < or = 0.002 and p < or = 0.020, respectively)., Conclusions: In anterior AMI, the ECG is useful to predict the LAD occlusion site in relation to its major side branches.

The renin angiotensin system plays an important role in the development of pulmonary artery remodeling and right ventricular hypertrophy in hypoxia-induced pulmonary hypertension as may occur in patients with COPD. Several polymorphisms of genes encoding for components of the renin angiotensin system such as the M235T polymorphism in the angiotensinogen gene, the 287-base-pair insertion (I)/deletion (D) polymorphism at intron 16 of the ACE gene, and the A1166C polymorphism in the angiotensin II type 1 receptor gene have been associated with an increased risk of cardiovascular diseases. With respect to the pulmonary circulation, only limited data exist on possible associations between polymorphisms of these genes and pulmonary hypertension and/or right ventricular hypertrophy. The objective of the present study was to investigate a possible relationship between polymorphisms of the renin angiotensin system and electrocardiographic evidence of right ventricular hypertrophy in patients with COPD. We therefore determined the angiotensinogen (M235T), angiotensin converting enzyme (I/D), and angiotensin II type 1 receptor (A1166C) genotypes in 87 patients with severe COPD and correlated these data with electrocardiographic parameters of right ventricular hypertrophy. Thirty-one patients (36%) of 87 patients with COPD showed electrocardiographic evidence of right ventricular hypertrophy. In the male, but not in the female, subgroup, the angiotensin-converting enzyme DD genotype was negatively associated with electrocardiographic evidence of right ventricular hypertrophy (male: chi2 = 3.8, p = 0.05; female: chi2 = 0.05, p = 0.82). We found no associations between the investigated polymorphisms in the angiotensinogen and angiotensin II type 1 receptor genes and electrocardiographic evidence of right ventricular hypertrophy.

Selective serotonin reuptake inhibitors (SSRIs) are the 'new' drugs of first choice for the treatment of depression in the older patient. Systematic studies on the effects of SSRIs on cardiac function are scarce, despite the high prevalence of cardiac disorders in the older depressed patient. This is a study which systematically assessed cardiac function by echocardiography in middle-aged and elderly depressed patients treated with SSRI. In a double-blind randomized trial, 20 patients were assigned to receive fluvoxamine 100 mg/day [DOSAGE ERROR CORRECTED] or fluoxetine 20 mg/day [DOSAGE ERROR CORRECTED] for 6 weeks. Cardiac function was assessed by left ventricle ejection fraction, aortic flow integral and early or passive/late or active mitral inflow, and electrocardiography. Neither SSRI significantly affected cardiac function. Compared with patients without a history of myocardial infarction and/or hypertension, patients with such a history showed a significant improvement in left ventricular ejection fraction. Despite our small study sample, these data indicate that both fluoxetine and fluvoxamine do not affect cardiac function adversely.

In a patient with pulmonary emboli, transesophageal echocardiography showed a thrombus straddling the foramen ovale (impending paradoxical embolism). Proximal pulmonary emboli were visualized by spiral computed tomography and subsequent surgical treatment, consisting of removal of intracardiac clot, closure of the open foramen ovale and pulmonary embolectomy, was successful.

In dialysis patients blood pressure can be well controlled with long dialysis (3 times a week for 8 h) in contrast to a more common short dialysis regime (3 times a week for 4 h). We studied whether the good blood pressure control in patients on long dialysis as compared to patients on short dialysis was associated with a decrease in extracellular fluid volume. Two-day interdialytic ambulatory blood pressure monitoring was performed in 26 non-diabetic patients on long dialysis, in 22 patients on short dialysis, matched for the years they were on dialysis treatment, and during 24 h in 19 healthy volunteers. After full equilibration, 24 h after dialysis, echography of the inferior caval vein was performed to determine fluid state. Cardiac dimensions and stroke index were measured by echocardiography. A blood sample was drawn for the determination of electrolytes and vasoactive hormones. 73% of the patients on short dialysis were using antihypertensive medication in contrast to none of the patients on long dialysis. However, blood pressure was significantly lower in patients on long dialysis (115 +/- 21/67 +/- 11 mm Hg) when compared to patients on short dialysis (143 +/- 26/81 +/- 16 mm Hg). Indexed caval vein diameter, left ventricular diameter index, and atrial natriuretic peptide were not significantly different in patients on long dialysis compared to patients on short dialysis. Also the cardiac index was comparable in patients on long and short dialysis. However, the total peripheral resistance index was significantly lower in patients on long dialysis compared to the patients on short dialysis and normal controls. The left ventricular mass index was increased in both patients on long and short dialysis compared to controls. We conclude that patients on long dialysis have adequate blood pressure control that seems mainly to be caused by a low total peripheral resistance. These data also suggest that factors other than a lower fluid state contribute to the good blood pressure control in patients on long dialysis.

Fabry's disease is an X-linked hereditary disorder resulting in accumulation of a glycolipid (galactosylgalactosyl glucosylceramide) due to deficiency of alpha-galactosidase A. The diagnosis can be made by histopathologic examination of skin biopsy, low activity of alpha-galactosidase in leucocytes and genetic examination. Treatment is symptomatic. We want to stress the multidisciplinary collaboration necessary to deal with this condition, in order to prevent acceleration of symptoms.

Objective: To determine frequency and clinical features of major depressive disorder according to DSM IV criteria in patients following a first myocardial infarction., Design: Questionnaire., Setting: Departments of Cardiology and Psychiatry, University Hospital Maastricht, the Netherlands., Method: Depression was assessed using the Zung 'Self-rating depression scale' (Zung-SDS) and the 'Symptom checklist' (SCL)-90 in 228 patients who filled the questionnaires out themselves (response: 60-70%), 1, 3, 6 en 12 months after their first heart attack. When the score on one or both lists was above threshold, the patient was invited for a clinical interview with a psychiatrist., Results: One month post infarction 10% were diagnosed with a major depressive episode, a percentage which increased to 34% one year post infarction. The clinical features of the depression in these patients were the same as in a matched sample of depressed psychiatric inpatients without a cardiac history, except that hostility was significantly increased in the post-infarction patients. There was no mortality., Conclusion: Depressive disorder is a frequent comorbid disease after a first myocardial infarction.

We evaluated the value of color and pulsed Doppler transesophageal echocardiographic parameters and of V waves in estimating the severity of mitral regurgitation (MR) in 62 consecutive patients (38 men and 24 women, aged 39 to 80 years) with angiographically proven chronic pure MR (15 grade I/II, 47 grade III/IV). Twenty patients were examined before cardiac surgery under general anesthesia. Sensitivity, specificity, and positive and negative predictive values of systolic pulmonary venous flow reversal for the presence of grade III/IV MR were 87%, 93%, 98%, and 64%, respectively, these were for jet areas > or = 8.0 cm2--66%, 100%, 100%, and 48%, for jet lengths > or = 50 mm--70%, 87%, 94%, and 48%, for enlarged V waves--86%, 38%, 83%, and 43%, and for either flow reversal or a jet area > or = 8.0 cm2--96%, 93%, 98%, and 88%. We conclude that a combination of measurements improved the negative predictive value considerably, which is of importance in a population with a high pretest probability of severe MR. Enlarged V waves are not reliable in predicting severe MR. The optimal cutoff value for jet area and jet length was lower in anesthesized patients than in conscious patients; in anesthesized patients, sensitivity, specificity, and positive and negative predictive values of jet area > or = 5.0 CM2 for grade III/IV MR were 67%, 100%, 100%, and 50%, respectively; these were 87%, 100%, 100%, and 71% for flow reversal. Because the results of mitral repair are often evaluated with transesophageal echocardiography during surgery, our findings have clinical implications for evaluation of severe MR in anesthesized patients: pulmonary venous flow direction is the first-choice measure; jet area can be used when a low cutoff point is chosen.

Various kinds of abnormal, asynchronous electric activation of the left ventricle (LV) decrease mechanical load in early versus late activated regions of the ventricular wall. Because myocardium usually adapts its mass to changes in workload, we investigated by echocardiography whether regional differences in wall thickness are present in two kinds of asynchronous electric activation of different origin and conduction pathway: epicardial ventricular pacing in dogs and left bundle branch block (LBBB) in patients. In six dogs, 3 months of epicardial LV pacing at physiologic heart rates decreased the thickness of the early activated anterior wall by 20.5 +/- 8.1% without significantly changing LV cavity area and septal thickness. In a retrospective study of 228 LBBB patients, the early activated septum was significantly thinner than the late activated posterior wall. The asymmetry most pronounced was as large as 10% in 28 patients with LBBB and paradoxic septal motion. No difference in regional wall thickness was present in 154 control patients. In conclusion, chronic asynchronous electric activation in the heart induces redistribution of cardiac mass. This redistribution occurs in hearts, which differ in impulse conduction pathway, disease, and species and is characterized by thinning of early versus late activated myocardium.

Objective: To test the hypothesis that in pregnancies complicated by intrauterine growth retardation (IUGR) maternal cardiovascular adaptation is already abnormal in the first weeks of pregnancy., Setting: University Hospital Maastricht, Maastricht, The Netherlands., Subjects: Fourteen healthy pregnant women, recruited from the subfertility clinic. Ten pregnancies were uneventful and four pregnancies resulted in the birth of growth retarded infants., Methods: Maternal cardiovascular status was followed longitudinally by combined M-mode and Doppler echocardiography. Studies were performed weekly between the fifth and 10th week, at 14, 25 and 35 weeks and postpartum. Differences between the two groups were analyzed by nonparametric tests., Results: In early pregnancy, the IUGR group differed from the normal group by a consistently smaller left atrial diameter and a cardiac output that failed to increase. Postpartum the subjects in the IUGR group had a significantly smaller left atrial diameter and faster mean circumferential fiber shortening., Conclusion: Maternal hemodynamic adaptation in the first weeks of pregnancy is defective in IUGR pregnancies, presumably associated with a concomitant inadequacy of the vascular filling state.

Acute or subacute myocardial rupture is a serious and often lethal complication of acute myocardial infarction. The role of an occluded or open culprit coronary artery on the occurrence of this complication is not clear. We therefore reviewed the perfusion status of the infarct-related coronary artery retrospectively in 57 patients who had an initially nonfatal rupture (group A) and 28 patients (including 9 patients from group A) with a postmortem diagnosis of myocardial rupture (group B). In 35 of the 57 patients in group A, a coronary angiogram was available. Complete occlusion or ineffective reperfusion was present in 30 (89%) of 35 patients. The remaining 22 patients of group A showed no clinical signs of reperfusion. All 28 patients of group B had inadequate reperfusion of the infarcted area on postmortem angiography and macroscopic examination of the coronary artery. Our observations suggest that myocardial rupture typically occurs in an infarcted area without reperfusion.

Objective: To test the hypothesis that volume adaptation in pregnancies complicated by fetal growth restriction (FGR) is already abnormal very early in pregnancy., Methods: In six pregnancies later complicated by FGR, volume homeostasis in the first 8 weeks was compared to that in ten normal pregnancies. Creatinine clearance, volume-dependent hormones, hemodilution-related variables, and ultrasonic cardiovascular dimensions were measured weekly between weeks 5 and 10, in the second and third trimesters, and postpartum. Differences between the two groups were analyzed by nonparametric tests., Results: Very early in pregnancy, pregnancies complicated by FGR differed from normal pregnancies in the following ways: smaller left atrial diameter, smaller collapsible part of the inferior vena cava, lower serum sodium concentration, and smaller fall in serum creatinine and urea., Conclusion: Fetal growth restriction is preceded by defective volume adaptation very early in pregnancy. It appears that the maternal compensation mechanisms are unable to resolve the transient state of vascular underfill seen in this period in normal gestation.

Introduction: This study was performed to determine the effect on the P wave of different hemodynamic loads to the heart., Methods and Results: Signal-averaged P wave ECG and atrial echocardiographic measurements were obtained from eight healthy male volunteers at rest and after infusion of 1000 mL of plasma expander (Haemaccel) over 15 minutes. These measurements were repeated 24 hours later at rest and after 0.8 mg of nitroglycerin given sublingually. The effect of positional changes was also studied. At rest the amplitude of the P wave and the time of the maximal the P wave amplitude were reproducible. Sitting increased heart rate variability; no significant changes of the P wave were found. Volume overload decreased the heart rate and increased the atrial size on echocardiography with changes in lead V1 (earlier appearance of the first positive deflection). Nitroglycerin administration increased heart rate and decreased the echocardiographic size of the atria, the latter not reaching statistical significance. Administration of nitroglycerin induced P wave amplitude rise in leads I and II. The maximal power in fast Fourier transformation for calculated orthogonal leads X and Y increased as well., Conclusions: Amplitude behavior in leads I, II, and V1 appears to correlate with load conditions, particularly with volume redistribution. In healthy men subtle changes in the P wave morphology after volume changes can be detected by the signal-averaged ECG. Application of these findings in patients following acute changes in circulation needs further investigation.

Objective: The aim was to determine whether measurement of the anterior-posterior diameter of the inferior vena cava (IVC) by ultrasonography, before and during deep inspiration, allows indirect information on baseline blood volume and changes in vascular filling state to be obtained in healthy subjects., Methods: Blood volume was measured in 12 volunteers by a standard radioactive isotope method. The IVC dimensions were measured by ultrasound in various positions. In addition, in 10 male subjects the effect on the IVC dimensions of volume loading was evaluated by rapid infusion of plasma expander. During and immediately following volume loading, the IVC dimensions and blood volume were remeasured., Results: Neither the baseline IVC diameters nor any combination of these variables correlated with the concomitant blood volume. Volume loading increased the anterior-posterior IVC dimensions linearly, the largest increase being observed with the maximum IVC diameter and the subject in supine position., Conclusions: It follows that ultrasonic IVC indices cannot be used as accurate indirect estimate of baseline blood volume, but provide reliable information on acute changes of the subjects' vascular filling state.

Objective: To determine the value of cross sectional Doppler echocardiography and derived indices of right ventricular pressure and function in the initial diagnosis of pulmonary embolism., Background: Most deaths from acute pulmonary embolism occur because of a delay in diagnosis. Ventilation-perfusion scans are not sufficiently sensitive, whereas angiography is invasive and associated with complications. The use of cross sectional Doppler echocardiography to assess acute changes in right ventricular filling pressure and function, and in pulmonary arterial systolic pressure and its relation to embolism has not been studied in a large population., Methods: 60 consecutive patients with acute symptoms or haemodynamic instability suggestive of pulmonary embolism were studied. Confirmatory investigations included a ventilation-perfusion scan (36 patients), angiography (18 patients), surgery (5 patients), or necropsy (5 patients)., Results: There was evidence of right ventricular pressure or volume overload in all. This took the form of increased right ventricular end diastolic diameter and leftward bulging of the interventricular septum in diastole (56 patients); tricuspid valve regurgitation (56 patients) with the peak velocity of the regurgitant jet > 2.6 m/s; and a low collapse index for the inferior vena cava of < 40%, indicating raised mean right atrial pressure (in 49 patients). Intracardiac or pulmonary thrombi were visualised in 10 patients. In 14 patients treatment was undertaken on the basis of the echocardiographic signs alone. Four of them (with visible thrombi) recovered: the other 10 died. Lung emboli were demonstrated in 4 of 5 patients in whom necropsy was performed., Conclusions: Cross sectional Doppler echocardiography is a sensitive technique for the rapid identification of right ventricular overload in acute pulmonary embolism. It enables further investigations on treatment to be appropriately directed without delay. Resolution of emboli can also be assessed by serial measurement of the described indices.

The value of exercise Doppler-echocardiography was studied in 60 patients with mitral valve stenosis. Patients were divided in three groups. In patients with a mitral valve area of more than 1.4 cm2, maximal and mean diastolic gradient over the mitral valve increased from 13.2 +/- 3.6 to 18.4 +/- 5.4 and from 5.2 +/- 1.9 to 8.8 +/- 3.0 mmHg, respectively. In patients with a mitral valve area in between 1.0 and 1.4 cm2, maximal and mean gradient increased from 19.0 +/- 8.0 to 28.1 +/- 8.9 and from 8.8 +/- 4.9 to 14.8 +/- 6.4 mmHg, respectively. In patients with a mitral valve area of less than 1 cm2, the maximal gradient increased from 21.5 +/- 5.8 to 34.2 +/- 8.7 and mean gradient increased from 11.8 +/- 4.1 to 20.3 +/- 5.8 mmHg. Mean tricuspid regurgitation velocity increased from 2.9 +/- 0.5 m/s to 3.6 +/- 0.5 m/s, indicating increase in right ventricular to right atrial pressure difference from 34 mmHg to 52 mmHg. We conclude that exercise during the Doppler-echocardiographic evaluation provides additional information about the hemodynamic significance of mitral stenosis and can therefore be of value in decision making.

The acute anatomic and valvular consequences of radiofrequency catheter ablation of accessory pathways were evaluated in 62 patients by means of serial echocardiographic examinations. Semiquantitative assessment of valvular incompetence and classification into one of four grades according to the width and the extension of the jet from the valvular orifice were carried out. Segmental wall motion abnormalities were evaluated semiquantitatively with four grades of severity (normal, hypokinesia, akinesia, or dyskinesia). New echocardiographic abnormalities were observed in five patients. One thrombus on the ventricular aspect of the mitral valve, three hemodynamically insignificant pericardial effusions, and one increase in severity of tricuspid incompetence were found 1 day after radiofrequency catheter ablation. We conclude that echocardiographic changes after radiofrequency ablation of accessory pathways are rare and of minor significance. These findings confirm the safety of the procedure.

To assess the hypothesis that echocardiographic variables vary as a function of baseline blood volume and change in response to changes in vascular filling state, we evaluated the relationship between the atrial and ventricular dimensions and left ventricular function, as measured by combined Doppler and M-mode echocardiography on the one hand, and blood volume as measured by a standard radioactive isotope technique on the other. Furthermore, we determined the effect of an increment in vascular filling state induced by plasma volume expansion. Test subjects were ten male and six female volunteers. Blood volume/kg was the only factor not different between male and female subjects and therefore suitable for our study. None of the echocardiographic variables correlated with blood volume/kg. Volume loading increased stroke volume, left atrial diameter, right atrial area, left ventricular end-diastolic dimension, mean velocity of circumferential fiber shortening and left ventricular ejection time. It is concluded that echocardiographic variables are unsuitable for estimating blood volume. Serial measurements of atrial dimensions and left ventricular dimensions are useful for detecting rapid changes in vascular filling state.

In 49 consecutive patients (27 men and 22 women, age range 44 to 86 years) presenting with acute symptoms and with subsequently proven pulmonary embolism, and without previous lung disease, the 12-lead electrocardiograms obtained at hospital admission were reviewed in a blinded fashion to identify electrocardiographic features suggestive of right ventricular overload. Pulmonary embolism was considered probable in 37 patients (76%), from the presence of > or = 3 of the following abnormalities: (1) incomplete or complete right bundle branch block (n = 33); which was associated with ST-segment elevation (n = 17) and positive T wave (n = 3) in lead V1; (2) S waves in leads I and aVL of > 1.5 mm (n = 36); (3) a shift in the transition zone in the precordial leads to V5 (n = 25); (4) Q waves in leads III and aVF, but not in lead II (n = 24); (5) right-axis deviation, with a frontal QRS axis of > 90 degrees (n = 16), or an indeterminate axis (n = 15); (6) a low-voltage QRS complex of < 5 mm in the limb leads (n = 10); and (7) T-wave inversion in leads III and aVF (n = 16) or leads V1 to V4 (n = 13), which occurred more often in patients with symptoms for > 7 days. In the 12 patients with normal electrocardiograms at admission, serial electrocardiograms revealed diagnostic features of embolism in an additional 3 patients. Two-dimensional Doppler echocardiography at admission revealed tricuspid valve regurgitation and an increased right ventricular end-diastolic diameter in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: The purpose of this study was to test the hypothesis that early pregnancy changes in volume homeostasis develop as a consequence of preceding changes in maternal hemodynamics., Study Design: Maternal cardiovascular function of 10 pregnant women was followed up by Doppler echocardiography. Vascular filling state and volume homeostasis were evaluated by echocardiographic index values, glomerular filtration rate, serum osmolality, and volume-regulating hormones. Studies were performed weekly in early pregnancy, in the second and third trimesters, and post partum. Changes relative to the fifth week and the consistency of changes between weeks 5 and 8 were evaluated by nonparametric statistics., Results: In early pregnancy cardiac output increased and afterload decreased. Concomitant increases in ultrasonic preload index values and glomerular filtration rate were accompanied by decreases in serum renin, Na+, and osmolality., Conclusion: These data support the concept that maternal hemodynamic adaptation to pregnancy is most likely triggered by a primary fall in systemic vascular tone. The resulting rapid fall in preload and afterload leads to a compensatory increase in heart rate and activation of the volume-restoring mechanisms. Subsequently cardiac output increases because of a rise in stroke volume, which develops because the vascular filling state normalizes, whereas the reduced afterload reduction is maintained.

In a patient with the Wolff-Parkinson-White syndrome, Ebstein's anomaly of the tricuspid valve, a right atrial Chiari net and a patent foramen ovale two unusual complications developed after surgical epicardial dissection combined with cryoablation of the anomalous pathway. The first complication was that ablation of the right atrial wall led to changes in interatrial pressure gradients and the development of a right to left shunt necessitating surgical closure of the atrial septal defect. The second complication was the development of a thrombotic mass in the Chiari net simulating on intracavity tumour, which also had to be removed surgically.

Little information is available regarding the incidence of aortic dissection after previous aortic valve replacement (AVR), and factors associated with its development. Therefore, a meta-analysis of the literature was performed, and a patient population was studied retrospectively. Data from published studies showed that 87% of 31 patients were men (mean age 60 years), and 68% were known to have systemic hypertension. A dilated ascending aorta was observed at the time of AVR in 88% of patients. AVR was performed because of pure aortic regurgitation in 55% of patients, and combined aortic stenosis and regurgitation in 23%. More than 50% of patients did not survive dissection. The present series consisted of 7 patients. Four patients were known to the department before dissection occurred, and the other 3 were referred by other hospitals. Eighteen of 330 patients with previous AVR whose data were stored in an echocardiographic data base had an ascending aortic diameter > 50 mm. Of these 18 patients, aortic dissection occurred in 4. Three of the remaining 14 patients underwent elective ascending aortic replacement. Characteristics including sex, age, severity of dilatation, presence of progression in diameter, left ventricular function and time interval after AVR were not helpful in determining a cumulative risk for developing dissection. Because dissection occurred in 4 of 18 patients (22%) with an ascending aorta diameter > 50 mm, it is suggested to consider replacement of the ascending aorta during AVR when a value of 50 mm is exceeded.

Objectives: To obtain information on the long-term effects of dynamic cardiomyoplasty on hemodynamics and muscle histology, this surgical method was evaluated in goats., Background: Dynamic cardiomyoplasty has been introduced as a new method to treat patients with severe cardiac failure., Methods: In 24 goats, the left latissimus dorsi muscle was wrapped around the heart. The muscle was then subjected to progressive electrical stimulation. In 16 goats, invasive transesophageal Doppler echocardiographic measurements and histologic evaluation of the latissimus dorsi muscle were performed at > or = 12 weeks after the wrapping., Results: Only two goats showed an increase in aortic and left and right ventricular pressures concomitant with increased aortic flow during latissimus dorsi muscle stimulation both before and after induction of cardiac failure using imipramine. This was accompanied by a preserved latissimus dorsi muscle structure and nearly complete transformation to type I muscle fibers. The remaining 14 goats showed extensive lipomatosis in the latissimus dorsi muscle, with severe intimal hyperplasia and proliferation of smooth muscle cells in the walls of the thoracodorsal artery and its branches. An increase in endoneural and endomysial connective tissue was observed, with some goats showing destroyed nerve branches near the electrodes. These findings differed from those observed after long-term electrical stimulation of goat latissimus dorsi muscle in situ., Conclusions: Dynamic cardiomyoplasty is of use in the treatment of severe heart failure if the histologic structure of the wrapped latissimus dorsi muscle remains intact. Long-term results in goats suggest that the current approach used in dynamic cardiomyoplasty may lead to deterioration of the wrapped muscle.

Because clinical indices of hydration state are insensitive, the estimation of correct postdialysis dry weight is still major problem. Recently, some new techniques have been introduced to assess postdialysis dry weight more accurately. The plasma concentrations of the biochemical markers atrial natriuretic peptide (ANP) and cGMP are related to intravascular hydration state. The echographically measured inferior caval vein diameter (VCD) is linked to right atrial pressure and blood volume (BV). Regional noninvasive conductivity measurements provide information about regional extracellular fluid volume (EFV). In this study of postdialysis ANP and cGMP concentrations, VCD and EFV yielded postdialysis diagnoses of hydration state in 18 patients on maintenance dialysis. In order to verify the established diagnosis, hemodynamic and BV changes during dialysis were studied. In postdialysis underhydrated patients, differentiated according to VCD and EFV standards, a pronounced decrease in BV, stroke volume, and left ventricular end-diastolic diameter compared with postdialysis normohydrated patients was observed. Hemodynamic and BV changes during dialysis were identical in the groups selected according to postdialysis ANP level. Only a difference in BV decrease was demonstrated between the groups selected according to postdialysis cGMP. Predialysis and postdialysis VCD correlated well with the corresponding EFV (r = 0.7 and r = 0.8, respectively). Because VCD and EFV were related and interpretation yielded diagnoses of postdialysis hydration state that were substantiated by the finding of classical hemodynamic features of underhydration, both are an asset in the diagnosis of postdialysis dry weight. cGMP values are less informative, and ANP does not provide any information at all.

In this paper, several newly developed techniques for the estimation of the fluid status in hemodialysis patients were reviewed. Whereas echography of the inferior caval vein and the measurement of ANP and cGMP levels merely provide information about the intravascular volume, conductivity measurements are able to detect changes in the extracellular and intracellular compartments without being able to differentiate between the intravascular and interstitial fluid spaces. Echography of the inferior caval vein as a tool to assess over- and underhydration has been successfully validated against objective standards as right atrial pressure, total blood volume and the change in hemodynamic parameters during dialysis. Conductivity measurements were significantly related to vena cava measurements before and after dialysis. Whereas ANP levels were significantly related to the vena cava diameter before dialysis, in another group of patients, only a significant relation between the vena cava diameter and cGMP was observed in patients with normal left atrial hemodynamics, whereas they were not in patients with a dilated left atrium. Furthermore, in normovolemic patients with mitral insufficiency, ANP levels after dialysis remained increased compared to patients without mitral insufficiency, suggesting that, in addition to volume expansion, also altered left atrial hemodynamics influence the release of cGMP and ANP. Conductivity measurements and ANP before and after dialysis were not related, whereas only cGMP after dialysis was significantly related to conductivity measurements. ANP and cGMP were not related to the change in hemodynamic parameters during dialysis, questioning their reliability in the assessment of underhydration.

Recombinant human erythropoietin therapy (ReHuEpo) at short term leads to an increase in systemic vascular resistance and to a decrease in cardiac index and skin microcirculatory flow. Long-term adaptive changes might occur. We studied the effects of ReHuEpo therapy on macrocirculation and skin microcirculation in 8 normotensive and normovolemic hemodialysis patients before and after, respectively, 4 and 14 months of treatment. The reported macrocirculatory changes at short term were at long term not significantly different as compared with the initial values. The mean arterial pressure remained unaltered, as might be explained by the slow correction of the hematocrit and the decrease in cardiac output in all initially long-lasting normotensive patients who were maintained normovolemic. Left ventricular end-diastolic dimensions decreased, and also the left ventricular muscle mass decreased, depending on the initial left ventricular muscle mass. The skin oxygenation improved, whereas the maximal capillary flow decreased both at short- and long-term ReHuEpo treatment. The number of capillaries in the nail fold remained unchanged. However, the percentage of tortuosity decreased significantly during ReHuEpo therapy.

Objective: Evaluation of the use of radiofrequency energy to interrupt accessory atrioventricular pathways., Design: Prospective study., Setting: University Hospital Maastricht., Method: The outcome is presented of radiofrequency catheter ablation of accessory atrioventricular pathways in our first 50 consecutive patients, with a total of 54 accessory pathways. All but one patient suffered from symptomatic tachycardias. A catheter electrode was positioned next to the accessory pathway and 30 second pulses of 40 W radiofrequency energy were used to interrupt the connection., Results: Complete block in conduction was accomplished in 44/54 (81%) of accessory pathways. No complications occurred. Success rate, procedure time and radiation dose were found to be related to the location of the accessory connection. The highest success rate was found in left free wall pathways (24/26; 92%), the lowest in right lateral pathways which seldom occur (1/4; 25%). The total procedure took 1-6 hours. The maximal duration of radiographic imaging was 2.5 hours., Conclusion: Although insufficient information on long-term efficacy is available, current results support the use of radiofrequency ablation of accessory pathways in institutions with expertise in the invasive management of cardiac arrhythmias. Technical improvements leading to reduction in procedure time and radiation dose will facilitate acceptance of this technique by patient and operator.

During the last decade dynamic cardiomyoplasty has been introduced as a new method to treat patients with severe heart failure. This procedure consists of the wrapping of the latissimus dorsi (LD) muscle around the heart with electrical stimulation of the muscle synchronous to cardiac contraction. The optimal pacing mode of the muscle, during the conditioning and working period of the LD muscle, is still unclear. The pace protocol, currently used worldwide, has a maximal number of muscle tetanic contractions of 100 per minute. Data are presented on the LD muscle contraction characteristics using that protocol. Both force measurements from six in situ stimulated goat LD muscles and x-ray evaluation of the movement of metallic clips on wrapped LD muscles in two patients were used. Results demonstrate that LD muscle force is well maintained at the maximal rate of 100 contractions per minute but relaxation is severely hampered. This may lead to diminished support of the failing heart and damage of the wrapped muscle. A pacing protocol is proposed using a lower maximal stimulation rate.

Objective: The value of intravenous imipramine in creating a reversible model of short term heart failure was evaluated in anaesthetised dogs., Methods: Acute effects of imipramine were studied in 11 dogs using invasive haemodynamic pressure measurements and two dimensional echo evaluation., Results: After a 30 min imipramine infusion (7.5 mg.kg-1.h-1), positive left ventricular dP/dtmax decreased from 1368(SEM 108) to 909(119) mm Hg.s-1 (p < 0.05), left ventricular end diastolic pressure increased from 8(1) to 12(2) mm Hg (p < 0.05), while left ventricular pressure decreased from 106(4) to 87(6) mm Hg (p < 0.05). Cessation of imipramine administration resulted within 60 min in partial restoration of cardiac function. This deterioration and subsequent recovery was also demonstrated with echocardiographic measurements, which showed a decrease in ejection fraction from 54(3)% to 28(2)% (p < 0.05). During administration of imipramine neither significant electrophysiological changes nor supraventricular/ventricular arrhythmias were seen. Repeated infusions of imipramine in three anaesthetised dogs with a two week interval showed the reproducibility of the haemodynamic effects and the recovery of ventricular function. Since the model was developed to evaluate the use of cardiomyoplasty in heart failure, the effect of imipramine was also evaluated on latissimus dorsi muscle contraction. Administration of imipramine did not affect skeletal muscle force development at the dosage used to create heart failure., Conclusions: This model can be used to produce short term reversible heart failure in anaesthetised animals to test the efficacy of supportive interventions like dynamic cardiomyoplasty, intra-aortic balloon pumping, and mechanical cardiac assist devices.

Nine patients (eight males) are reported with one or more episodes of circulatory collapse in the absence of overt heart disease or other known causes of arrhythmias; sudden arrhythmic death occurred in one of these patients. Age at first episode ranged from 16 to 41 (mean, 28) years. In seven patients, ventricular fibrillation was documented at the time of resuscitation. One patient had ventricular flutter. In the remaining patient, documentation of the arrhythmia during the collapse was not available. Four patients had frequent early ventricular premature beats, and in three of these patients, they were accompanied by episodes of rapid nonsustained polymorphic ventricular tachycardia. Failure to suppress this ectopic activity by drug therapy seems to be of prognostic significance. Of the three patients showing persistence of frequent early ventricular premature beats, one died suddenly, and two had recurrences of symptomatic arrhythmic episodes. The value of noninvasive and invasive tests in the management of these patients is not clear, with the exception of exercise testing in patients with exercise-related arrhythmias and long-term electrocardiographic monitoring in patients with frequent spontaneous ventricular ectopic activity. Follow-up varied from 21 to 192 (mean, 84) months. One patient died suddenly 21 months after his first collapse. Selection of antiarrhythmic drug therapy was largely empirical. In view of the relative rarity of sudden arrhythmic death in the absence of heart disease and the many uncertainties about its mechanism(s) and management, a worldwide registry of these patients is suggested.

The purpose of the study was to evaluate the effect of antiischemic treatment on left ventricular function in selected patients with unstable angina pectoris that was due to severe proximal left anterior descending coronary artery narrowing and to identify subgroups liable to an adverse outcome (mean term 2.7 years). Effect of antiischemic treatment on systolic and diastolic left ventricular wall motion was studied in 35 patients who had unstable angina pectoris and an electrocardiogram that indicated severe proximal left anterior descending coronary artery narrowing. Treatment consisted of either a revascularization procedure (17 patients) or antianginal drug therapy (18 patients). All patients underwent a two-dimensional echocardiographic study within 48 hours (mean 20 hours) of entry into the study. This study semiquantitatively analyzed systolic performance of the ischemia-related segments by calculation of a total wall motion score. In 16 patients this investigation was combined with a continuous detailed recording of only the apical interventricular septal wall motion. This detailed study included measurements for regional function by providing a typification of the pattern of systolic and early diastolic excursion of the endocardial border of the apical interventricular septum. A repeat ultrasonic study was performed at least 1 month (median 2 months, 7 days) after admission. Results of the systolic wall motion analyses of all 35 patients showed, in both treatment groups, a significant improvement in systolic wall motion of the anterior and apical segments (mean total wall motion score at early study vs late study: revascularization, 6.9 vs 2.2 and medical therapy, 4.6 vs 1.0).(ABSTRACT TRUNCATED AT 250 WORDS)

A young patient is reported with an aneurysm of the left atrial appendage having supraventricular arrhythmias and a period of chest pain accompanied by a rise in cardiac enzymes. Compression of the left anterior descending coronary artery by the aneurysm was felt to be responsible for the myocardial injury.

Seven of 17 patients with incessant supraventricular tachycardia caused by an accessory pathway with a long retrograde conduction time were seen with symptoms or echocardiographic signs of a tachycardia-induced cardiomyopathy. Three patients were in New York Heart Association functional class II with dyspnea and four were in class III. Eight patients (six with tachycardia-induced cardiomyopathy) underwent surgery because of failure of medical treatment (including one patient in functional class I) and one underwent direct current catheter ablation of the atrioventricular (AV) node. In six patients echocardiograms recorded before and after the procedure were available. Before surgery or direct current ablation the mean left ventricular ejection fraction was 36.3 +/- 8.7%, the left ventricular end-diastolic diameter 55.7 +/- 7.6 mm and the left ventricular end-systolic diameter 44.3 +/- 7.8 mm. A mean of 21.6 +/- 6.8 months after the procedure the mean left ventricular ejection fraction increased to 58.6 +/- 8.0%, the left ventricular end-diastolic diameter decreased to 49.0 +/- 3.6 mm and the left ventricular end-systolic diameter decreased to 32.2 +/- 2.7 mm; all six patients were in functional class I. These results confirm that control of incessant tachycardia leads to a regression of symptoms and signs of cardiomyopathy and progressive normalization of the dimensions of the heart. Because of these findings, surgery should be considered early in patients with an accessory AV pathway and incessant tachycardia. The presence of a tachycardia-induced cardiomyopathy should therefore be an indication for surgery rather than a contraindication.

Epicardial cryosurgery for ablation of atrioventricular accessory pathways has surgical advantages. However, it is applied directly to the valve base. To assess the risk of valve impairment, 10 anaesthetized dogs were subjected to standardized epicardial cryosurgery of the right atrioventricular junction. Two of these underwent sham procedure (dissection only). Valve function was assessed by colour Doppler echocardiography preoperatively and at 2 days, 1 week, 2 weeks and 10 weeks postoperatively. Three out of the eight animals subjected to cryosurgery developed moderate (grade 2/4) tricuspid insufficiency, which appeared at 1 week postoperatively, following regression of congestive oedema. Two out of the three cases of TI were associated with leaflet prolapse. No tricuspid insufficiency was seen in the sham-operated animals. At the end of each interval two animals were killed for histological examination. Histological examinations showed that cryolesions extended a maximum of 3 mm into the valve leaflet. The tricuspid insufficiency is attributed to the extensive scarring (including chondroid metaplasia), which causes retraction and restricted motion of the annulus. It is concluded that cryolesions may impair atrioventricular valve function. Patients undergoing cryosurgery should be monitored postoperatively by echocardiography for atrioventricular valve insufficiency.

Changes of macro- and microcirculation during haemodialysis and fluid removal are probably dependent on ultimate fluid status and on the efficacy of various regulation mechanisms, especially the catecholamines. This was studied in 20 chronic dialysis patients. Pre- and postdialysis stroke volume, mean arterial pressure, heart rate and systemic vascular resistance were measured. Furthermore, microcirculation was studied by Laser Doppler flow and by intravital microscopy of finger nail fold, measuring red blood cell velocity and capillary density. Pre- and postdialysis noradrenaline and adrenaline were measured. Nine patients proved to be hypovolaemic after dialysis (group I) and 11 patients proved to be normovolaemic or less hypervolaemic (group II) according to vena cava inferior parameters. There was a significant decrease of mean arterial pressure and stroke volume in group I, and an increase of heart rate, whereas in group II there was only a decrease of mean arterial pressure. Systemic vascular resistance did not change in both groups. Noradrenaline decreased although not significantly in both groups, whereas in group I adrenaline increased significantly. There was a significant decrease of skin perfusion in group I, whereas in group II there was a significant increase. Capillary density increased significantly in group II after reaching normovolaemia. Underhydration was leading to a decrease of skin microcirculation on the basis of a decrease of stroke volume and an increase of adrenaline levels. In hypervolaemic patients, who were ultrafiltrated to normovolaemia, skin microcirculation improved on the basis of a decrease of arterial and venous pressure and consequently a decrease of the myogenic response as a local autoregulatory effect.

In 9 chronic hemodialysis patients, treated with recombinant human erythropoietin (rHuEpo), longitudinal studies were performed to investigate possible changes in macro- and microcirculatory parameters during normovolemia, as assessed echographically by determining the inferior vena cava diameter and adjusting dialysis dry weight. Hematocrit increased from 19 +/- 4 to 33 +/- 5% (p less than 0.001). Systemic vascular resistance increased from 1,020 +/- 259 to 1,283 +/- 245 dyn/s/cm-5 (p less than 0.02), while mean arterial pressure remained unchanged. Cardiac index decreased (4.9 +/- 1.4 to 3.8 +/- 0.9 liters/min/m2; p less than 0.02), caused by a decrease in heart rate (87 +/- 21 to 75 +/- 16 beats/min; p less than 0.02) and stroke index (59.9 +/- 15.2 to 51.0 +/- 10.7 ml/m2; p less than 0.02). Red blood cell volume increased (468 +/- 105 to 858 +/- 203 ml/m2; p less than 0.001) and plasma volume decreased inversely ([125I]-albumin; 2,008 +/- 338 to 1,664 +/- 225 ml/m2; p less than 0.001), whereas total blood volume remained unaltered (2,476 +/- 397 to 2,518 +/- 352 ml/m2; n.s.). Total body weight increased (57.8 +/- 12 to 62.1 +/- 12 kg; p less than 0.02), indicative of an anabolic effect of rHuEpo therapy. Skin capillary circulation as measured by transcutaneous oxymetry at 37 degrees C skin temperature impaired, reflected by the increase of the time to peak after arterial occlusion (82 +/- 21 to 121 +/- 25 s; p less than 0.02). The reactive hyperemic response following the release of occlusion showed a significant increase at high hematocrit (10.7 +/- 4.2 to 16.6 +/- 5.3 mm Hg; p less than 0.02), whereas resting transcutaneous Po2 values showed a slight but not significant increase (2.3 +/- 1.3 to 4.7 +/- 3.3 mm Hg; n.s.). The high number of pathological capillaries in hemodialyzed patients might be an additional factor for the increase in systemic vascular resistance.

To study possible beta-blocking effects of propafenone, a class 1c antiarrhythmic agent, electrocardiographic variables were studied at rest and during exercise. Forty-two patients with symptomatic ventricular arrhythmias were included. In 31 patients, exercise electrocardiograms before and after propafenone were available for study. The mean dose of propafenone was 603 mg for all 42 patients, 585 mg for patients undergoing exercise testing (range 450-1200). At rest, the PR interval, duration of P wave and QRS complex changed significantly without any change in the resting heart rate and QTc interval. During exercise there were no changes after propafenone in peak heart rate, PR interval, QTc interval, duration of exercise, or blood pressure. We conclude that, while class I effects are evident both at rest and after exercise, no clinically significant beta-blocking effects of propafenone could be demonstrated either at rest or during exercise.

Intraluminal vena caval filters, inserted via the transvenous approach, are used often in the prevention of recurrent pulmonary embolism. Until lately, such filters have been unremovable. In a recent case, however, we treated a patient who experienced acute massive pulmonary embolism after having undergone an emergency right hemicolectomy. He underwent a successful emergency pulmonary embolectomy with the help of cardio-pulmonary bypass; to prevent recurrent embolism, we inserted a removable intracaval filter through the right atriotomy with an introducer set. On the 7th postoperative day, the absence of significant residual thrombi was confirmed by means of phlebography, and the caval filter was removed percutaneously via the femoral approach. Although the value of routine use of the filter in this application has yet to be established, we feel that it warrants further investigation because it relieves the surgeon, during an emergency procedure, of the need to decide quickly whether or not to place a filter. The question becomes one of whether or not to remove the filter, and that decision can await the results of proper postoperative diagnostic studies.

The relationship between inferior vena cava diameter (VCD), collapse-index (CI) determined by echography, and alpha-human atrial natriuretic peptide (alpha-h-ANP) concentrations were studied in 19 chronic haemodialysis patients. A significant correlation was found between VCD and alpha-h-ANP before dialysis (r = 0.78; P less than 0.0001). No such correlation was found between CI, left atrial diameter and left ventricular end-diastolic diameter, and alpha-h-ANP values. In nine patients who according to vena cava indices were hypervolaemic before dialysis (group I), alpha-h-ANP concentrations were significantly greater than in ten normo- or hypovolaemic patients (group II): 392.8 +/- 134.1 pg/ml and 168.0 +/- 62.5 pg/ml respectively. Although the same amount of fluid was ultrafiltrated in both groups, alpha-h-ANP decreased significantly in group I only, whereas in group II the decrease was not significant: 392.8 +/- 134.1 to 185.2 +/- 81.7 (P less than 0.001); 168.0 +/- 62.5 to 130.0 +/- 59 respectively. After achieving normovolaemia alpha-h-ANP concentrations in patients with a mitral valve insufficiency grade I was doubled compared to normovolaemic patients without mitral valve insufficiency, suggesting that alpha-h-ANP release will also occur from the left atrium. In the latter group alpha-h-ANP values were approximately doubled compared to healthy controls. The highly significant correlation between VCD before dialysis and changes in alpha-h-ANP during dialysis with fluid removal underlines the value of vena cava diameter in estimating volume status.

A case is described of the development of an inferior caval vein thrombus and subsequent pulmonary embolism after right heart catheterization. The caval thrombus was diagnosed by echography. After six weeks of anticoagulant therapy the thrombus had resolved. The indication for prophylactic heparinization is discussed.

Using echography, the diameter of the inferior vena cava (IVC) and its decrease on deep inspiration (collapse index) were evaluated in haemodialysis patients. The diameter of the IVC was expressed as an index to the body surface area (VCD) in mm/m2. Non-linear regression analysis in predicting mean right atrial pressure by VCD (mm/m2) and collapse index revealed a good correlation (r = 0.92; P less than 0.001) in both measurements. These results indicate that the IVC indices can be used as a parameter for both high and low filling pressures. Over-hydration (mean right atrial pressure greater than 7 mmHg) was defined as a collapse index of less than 40% and a VCD of more than 11.5 mm/m2, and underhydration (mean right atrial pressure less than 3 mmHg) as a VCD of less than 8 mm/m2 and collapse index of above 75%. In 22 patients in whom dry weight was determined on clinical grounds, only six had a correct dry weight according to IVC indices. Reliability of IVC indices for estimation of body fluid status was proved by the fact that during haemodialysis with fluid removal, postdialysis underhydrated patients according to IVC indices showed a decrease of mean arterial pressure and stroke volume, and an increase of heart rate. No such changes were observed in postdialysis normovolaemic and hypervolaemic patients, according to the vena cava indices. Furthermore, blood volume in normo- and hypervolaemic patients decreased much less than in hypovolaemic patients, despite the same amount of ultrafiltration. Total blood volume (ml/m2) and VCD (mm/m2) correlated significantly (r = 0.61; P less than 0.001), whereas there was no significant correlation between collapse index and blood volume.(ABSTRACT TRUNCATED AT 250 WORDS)

One hundred eighty of 1260 patients consecutively admitted to the hospital because of unstable angina pectoris had the typical ST-T segment changes suggestive of a critical stenosis in the proximal LAD. In 108 patients the ECG abnormalities were present at the time of admission. In the remaining 72 patients they developed shortly thereafter. The difference between these two groups was a longer duration of anginal complaints in the former (mean 2.3 days). Results of coronary angiography, performed a mean of 4.6 days after the last attack of chest pain, showed 50% or more narrowing in the proximal LAD in all patients. Thirty-three patients had complete occlusion of the LAD and 75 had collateral circulation to the LAD. Results of left ventricular angiography showed abnormal systolic left ventricular wall motion in 137 patients and normal systolic motion in the remaining 43 patients. The difference between these two groups was a shorter mean time interval between the last attack of chest pain and angiography in the former group (p less than 0.001). Twenty-four patients had only abnormal diastolic wall motion. Twenty-one patients had a small increase in the creatine kinase level at the time of admission. Fifteen patients (nine before and six during early revascularization) had an anterior wall myocardial infarction in the hospital; these patients had a patent but severely narrowed LAD and a low incidence of collateral circulation to the LAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial dissociation is an electrocardiographic phenomenon characterized by the occurrence of two separate atrial rhythms. A patient is presented, showing electrocardiographic signs suggestive for atrial dissociation. The dissociated, non-conducted, atrial rhythm showing micro-oscillations after its P wave, is shown to be a respiratory artifact. It is concluded that the micro-oscillations seen on the surface electrocardiogram after a dissociated P wave are probably diagnostic for pseudo-atrial dissociation.