Filippos Triposkiadis

Left Atrial Mechanical Function in the Healthy Elderly: New Insights From a Combined Assessment of Changes in Atrial Volume and Transmitral Flow Velocity

To assess left atrial mechanical function in the elderly, 35 old (age > 70 years) and 18 sex-matched young (age < 50 years) healthy subjects were studied. Transmitral flow velocities were recorded with pulsed Doppler echocardiography. Left atrial volumes were measured echocardiographically at mitral valve opening (maximal) and closure (minimal) and at onset of atrial systole (P wave of the electrocardiogram) according to the biplane area-length method. Left atrial passive emptying was assessed with the passive emptying volume (maximal-volume at onset of atrial systole) and fraction (passive emptying volume/maximal). Left atrial active emptying was assessed with the active emptying volume (volume at onset of atrial systole-minimal) and fraction (active emptying volume/volume at onset of atrial systole) and with left atrial ejection force = 0.5.blood density.volume at onset of atrial systole.active emptying fraction.(A velocity)2/A integral. Left atrial volumes were greater in old compared with young subjects (maximal: 31 +/- 10 cm3/m2 vs 24 +/- 8 cm3/m2, p = 0.02; at onset of atrial systole: 23 +/- 8 cm3/m2 vs 15 +/- 5 cm3/m2, p = 0.0002; minimal: 13 +/- 5 cm3/m2 vs 9 +/- 4 cm3/m2, p = 0.001). Passive emptying volume and fraction were lower (7.8 +/- 1.7 cm3/m2 vs 9.2 +/- 3.2 cm3/m2 [p = 0.04] and 26.4% +/- 9.8% vs 37.9% +/- 11.2% [p = 0.003], respectively), whereas atrial ejection force and active emptying volume were greater in old compared with young subjects (6.8 +/- 3.3 kdynes/m2 vs 4.2 +/- 2.8 kdynes/m2 [p = 0.007] and 9.2 +/- 4.1 cm3/m2 vs 5.7 +/- 2.9 cm3/m2 [p = 0.002], respectively). The active emptying fraction was similar in the two groups (39.7% +/- 11% vs 38.4% +/- 13%; difference not significant). Thus advanced age is associated with depressed left atrial passive emptying function and increased left atrial volume. Left atrial dilation contributes to an increase in atrial ejection force and the amount of blood ejected during left atrial systole and may represent an important compensatory mechanism in this age population.

Retrograde nontransseptal balloon mitral valvuloplasty. Immediate results and long-term follow-up.

BackgroundPercutaneous retrograde nontransseptal balloon mitral valvuloplasty is a new technique developed in our institution for opening a stenotic mitral valve. This technique is based on a new, externally steerable cardiac catheter that enters the left atrium retrogradely via the left ventricle. Methods and ResultsThe technique was used in 86 consecutive patients (18 men and 68 women; mean age, 51±11 years). Dilatation of the stenotic mitral valve was achieved in 85 of the 86 patients. After the procedure, mitral valve area increased from 0.92±0.22 to 2.1490.54 cm2 and transmitral gradient decreased from 16±6 to 5±2 mm Hg. Major complications, such as cardiac perforation, embolic events, or death, were not encountered. Severe mitral regurgitation (>2+) developed in three patients (3.5%). In two patients (2.4%), there was major injury of the femoral artery. The maintenance of the initial improvement was similar to that found in studies that used transseptal techniques. The restenosis rate during the 2-year follow-up was 15.4%. ConclusionsThe immediate and long-term findings of this study indicate that retrograde percutaneous nontransseptal balloon mitral valvuloplasty is an effective and safe procedure with an acceptable major complication rate. Moreover, this new technique has the advantage that it does not involve puncture and dilatation of the interatrial septum, although it may occasionally lead to arterial damage. Further studies will show whether it may really be considered as an alternative method or method of choice for percutaneous balloon mitral valvuloplasty.

Left atrial myopathy in idiopathic dilated cardiomyopathy

To investigate whether left atrial systolic dysfunction in dilated cardiomyopathy is the result of left atrial dilatation, atrial involvement in the myopathic process, or both, 20 patients with aortic stenosis, 14 patients with idiopathic dilated cardiomyopathy, and 10 normal control subjects were studied. Left atrial volumes (cubic centimeters) were echocardiographically measured at mitral valve opening (maximal), mitral valve closure (minimal), and onset of atrial systole (P wave of the electrocardiogram) with the biplane area-length method. Atrial systolic function was assessed by calculating the active emptying fraction, equal to (volume at onset of atrial systole minus minimal volume)/volume at onset of atrial systole. Heart rate was similar in patients with aortic stenosis and dilated cardiomyopathy (83 +/- 11 vs 86 +/- 15 beats/min, respectively). Maximal volume was similar in patients with aortic stenosis (74.8 +/- 26.4 cm3) and dilated cardiomyopathy (79.7 +/- 25.3 cm3) but greater (p < 0.0001) than in control subjects (46.4 +/- 11.9 cm3). Active emptying fraction was inversely related to volume at onset of atrial systole and to tension at end of atrial systole (aortic stenosis r = -0.61 and r = -0.81, respectively; dilated cardiomyopathy r = -0.79 and r = -0.66, respectively). At any given level of volume at onset of atrial systole and tension at end of atrial systole, however, active emptying fraction was lower in patients with dilated cardiomyopathy compared with those with aortic stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Relation of exercise capacity in dilated cardiomyopathy to left atrial size and systolic function

Abstract There is evidence to suggest that abnormalities of left ventricular diastolic function rather than systolic function may be the most important determinants of the effort tolerance of patients with chronic heart failure. 1 Because left atrial (LA) function is closely related to left ventricular diastolic function, it was hypothesized that the exercise capacity of patients with dilated cardiomyopathy is related to LA size and systolic function. The present study was undertaken to test this hypothesis.

Resistance to activated protein C and FV Leiden mutation in patients with a history of acute myocardial infarction or primary hypertension

This study was designed to investigate both resistance to activated protein C (APC-R) and the factor FV Q506 mutation incidence in patients with a history of acute myocardial infarction (AMI) and patients with primary hypertension (PH), a high-risk group for arterial thrombosis. Eighty patients with a history of AMI (group A), 160 patients with a history of PH (group B), and 124 age-matched controls without arterial disease (group C) were studied. APC-R was determined using the Coatest APC Resistance Kit of Chromagenix, Sweden. The prevalence of the FV Q506 mutation was estimated by DNA analysis (Bertina method). The prevalence of the FV Q506 mutation was 20%, 13.75%, and 8% in groups A, B, and C, respectively (A v C P = .0466). The prevalence of APC-R was 47.5% in group A v 13% in group C (P < .0001) and 36.25% in group B v 13% in group C (P < .0001). The response to activated protein C expressed as mean value +/- SD was 2.05 +/- 0.33 in group A v 2.56 +/- 0.46 in group C (P < .05) and 2 +/- 0.22 in group B v 2.56 +/- 0.46 in group C (P < .05). These findings suggest that patients with a history of AMI or PH have a significantly increased incidence of both APC-R and FV Q506 mutation compared with the control group. These findings support the hypothesis that these anticoagulant defects may be risk factors for arterial thrombosis.

Effect of atrial fibrillation on exercise capacity in mitral stenosis

To determine the preoperative and postoperative effect of atrial fibrillation (AF) on exercise capacity in mitral stenosis, 12 digitalized patients in AF (7 women and 5 men, age 52 +/- 6.1 years) and 10 in sinus rhythm (5 women and 5 men, age 46 +/- 5 years) underwent maximal cardiopulmonary exercise testing according to Webers protocol and Doppler echocardiographic examination before and at 3 and 6 months after mitral valve replacement. The ratio of right ventricular acceleration to ejection time was used as an estimate of mean pulmonary artery pressure. Preoperative exercise duration (6.8 +/- 1 vs 8 +/- 2 minutes), peak oxygen consumption (9.7 +/- 3 vs 12.3 +/- 3 ml/kg/min), and right ventricular acceleration to ejection time ratio (0.34 +/- 0.07 vs 0.34 +/- 0.08) were not significantly different between patients with AF and those in sinus rhythm. Postoperative improvement in these parameters was lower in patients with AF than in those in sinus rhythm: exercise duration at 3 months, 7.5 +/- 2 vs 11.9 +/- 2 minutes (p < 0.001); at 6 months, 9 +/- 2 vs 12 +/- 2 minutes (p < 0.001); peak oxygen consumption at 3 months, 10.8 +/- 3 vs 17.5 +/- 3 ml/kg/min (p < 0.001); and at 6 months, 11.9 +/- 3 vs 17.8 +/- 3 ml/kg/min (p < 0.001); right ventricular acceleration to ejection time ratio at 3 months, 0.35 +/- 0.08 vs 0.42 +/- 0.05 (p < 0.05); and at 6 months, 0.38 +/- 0.05 vs 0.44 +/- 0.05 (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Relation of left atrial volume and systolic function to the hormonal response in idiopathic dilated cardiomyopathy

We studied the relation of left atrial mechanical function to the hormonal response in 14 patients with idiopathic dilated cardiomyopathy. Left atrial volumes were echocardiographically measured at mitral valve opening (maximal), at onset of atrial systole (onset of the P wave of the electrocardiogram) and at mitral valve closure (minimal) from the apical 2- and 4-chamber views using the biplane area-length method. Left atrial systolic function was assessed with the left atrial active emptying fraction ([volume at onset of atrial systole-minimal]/[volume at onset of atrial systole]). Plasma renin activity, aldosterone and atrial natriuretic peptide plasma levels were determined using commercially available kits. Left atrial maximal volume was directly, and left atrial active emptying fraction was inversely related to plasma renin activity (r = 0.60, P = 0.02 and r = -0.59, P = 0.026, respectively), aldosterone (r = 0.61, P = 0.02 and r = -0.53, P = 0.048) and atrial natriuretic factor (r = 0.79, P = 0.0009 and r = -0.62, P = 0.01) plasma levels. Thus, increased left atrial size and depressed left atrial contractile performance are associated with increased hormonal response in idiopathic dilated cardiomyopathy.

Lack of a Thrombotic Tendency in Patients with Acute Myocardial Infarction and Angiographically Normal Coronary Arteries

The hematological profile of 12 patients with acute myocardial infarction and normal coronary arteriographic findings was compared to that of 8 patients with acute myocardial infarction associated with obstructive coronary artery disease, and of 12 patients with no evidence of myocardial infarction and normal coronary arteriographic and left ventriculographic findings who served as control. There were no significant differences in the hematological profile among the 3 groups, suggesting lack of a thrombotic tendency in patients with acute myocardial infarction and normal coronary arteriographic findings.

Factors affecting the postoperative exercise capacity of patients with mitral stenosis and aortic regurgitation.

Factors affecting the exercise capacity of patients with mitral stenosis (MS) and aortic regurgitation (AR) are incompletely understood. Accordingly, exercise capacity was assessed in 13 patients with MS and in 13 with AR by means of cardiopulmonary exercise testing before as well as 3, 6 and 12 months after valve replacement. Left- and right-ventricular function were evaluated echocardiographically. Both in MS and in AR exercise capacity expressed by maximal oxygen consumption (VO2max) increased significantly after valve replacement and was directly related to right ventricular (RV) function assessed by the ratio of RV acceleration time to RV ejection time (r = 0.87, p < 0.001 and r = 0.74, p < 0.001, respectively) and inversely related to left atrial diameter (r = -0.72, p < 0.001 and r = -0.76, p < 0.001, respectively). No relation between VO2max and resting left-ventricular function was found. Thus, the postoperative improvement in the exercise capacity both in mitral stenosis and in aortic regurgitation is associated with an improvement in right-ventricular function and a decrease in left-atrial size.

Sinus node dysfunction in acute inferior myocardial infarction : Role of sinus node artery and clinical course in patients with one-vessel coronary artery disease

To determine the role of the sinus node artery and the clinical course in postmyocardial infarction sinus node dysfunction, 27 patients with acute inferior myocardial infarction and single-vessel coronary artery disease were studied. In 13 patients (group 1) the infarct-related coronary artery was occluded proximally and in 14 (group 2) distally to the site of origin of the sinus node artery. At electrophysiology, performed 10 +/- 3 days from the acute event, basal and intrinsic heart rate were lower in group 1 compared to group 2 patients (54 +/- 4.8 vs. 69 +/- 7 beats/min, p = 0.001, and 66 +/- 7 vs. 76 +/- 8 beats/min, p = 0.006, respectively) while basal and intrinsic corrected sinus node recovery times were prolonged in group 1 compared to group 2 patients (585 +/- 49.3 vs. 324 +/- 61.3 ms, p = 0.0001, and 601 +/- 39.1 vs. 335 +/- 73 ms, p = 0.0001). During a 6-month follow-up no episodes of dizziness, syncope or angina were reported. Moreover, at the end of follow-up resting heart rate (70 +/- 11 vs. 73 +/- 7 beats/min, nonsignificant), maximal exercise heart rate (166 +/- 19 vs. 170 +/- 23 beats/min, nonsignificant), and exercise time (491 +/- 120 vs. 480 +/- 155 s, nonsignificant) were similar between the two groups and no exercise-induced ischemic ST segment depression was observed. Sinus node dysfunction in patients with inferior myocardial infarction and one-vessel disease is related to the occlusion of the infarct-related coronary artery proximal to the site of origin of the sinus node artery and is not associated with increased cardiovascular morbidity in the first 6 months from the acute event.