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[Atrial filling fraction predicts left ventricular systolic function after myocardial infarction: pre-discharge echocardiographic evaluation].

Aim of the study was to examine the relation between Doppler-derived indices of left ventricular diastolic and systolic function early after myocardial infarction. Fifty-three patients (31 males, 22 females) recovering from acute myocardial infarction underwent predischarge Doppler echocardiographic examination. Patients with age > 70 years, previous myocardial infarction, more than mild mitral and aortic regurgitation, mitral and aortic stenosis were excluded. Twenty-two healthy subjects (13 males; 9 females) free of coronary risk factors were selected as the control group. Both end-diastolic and end-systolic volumes and ejection fraction were measured by two-dimensional echocardiography. Pulsed Doppler was used to evaluate mitral inflow and left ventricular outflow velocity patterns. The following indices were measured: peak velocity of early (E) and late (A) flows, ratio of E/A peak velocities, ratio of early to late time velocity integrals, atrial filling fraction (time velocity integral A / time velocity integral of flow during total diastole) and deceleration time of E wave for mitral inflow; peak and time-velocity integral for left ventricular outflow. Stroke volume and cardiac output were obtained by pulsed Doppler using the left ventricular outflow method. The two groups were comparable for age, with blood pressure (p < 0.05) and heart rate (p < 0.01) reduced in myocardial infarction patients. Both end-diastolic and end-systolic volumes were significantly higher (both p < 0.0001) and ejection fraction (p < 0.0001) lower after myocardial infarction. Also stroke volume and cardiac output (both p < 0.0001) were reduced in myocardial infarction patients. No significant difference in Doppler indices of diastolic function was observed between the two groups, except for shortened deceleration time (p < 0.0001) in myocardial infarction patients. Multilinear regression analyses were performed separately into the two groups to identify determinants of left ventricular systolic function. After adjusting for age, heart rate, systolic blood pressure and both end-diastolic and end-systolic volumes, atrial filling fraction was an independent predictor of stroke volume, with a direct relation (beta coefficient = 0.53, p < 0.001), in myocardial infarction patients but not in health subjects. In conclusion, our study confirms the pseudonormalization of diastolic pattern after myocardial infarction. The direct relation between atrial filling fraction and stroke volume indicates the importance of atrial contribution to maintain an adequate systolic performance in patients with myocardial infarction.

Atrial Function, Right↗

Influence of heart rate and atrial transport on left ventricular volume and function: relation to hemodynamic changes produced by supraventricular arrhythmia.

The response of the left ventricle to pacing-induced changes in heart rate and the atrioventricular (A-V) relation was examined with equilibrium gated radionuclide ventriculography in 20 patients who had normal ventricular function after surgery for recurrent supraventricular tachycardia. In 10 patients count-derived left ventricular ejection fraction, end-diastolic volume and stroke volume were measured during sinus rhythm and during atrial pacing at 120, 140 and 160 beats/min. In the other 10 patients similar determinations were made during sequential A-V and simultaneous ventricular and atrial (V/A) pacing, both at rates of 100 and 160 beats/min. Left ventricular ejection fraction did not change significantly with atrial pacing (from 0.65 +/- 0.02 [mean +/- standard error of the mean] at a baseline sinus rate of 91 +/- 3 beats/min to 0.62 +/- 0.03 at 160 beats/min) despite a progressive decrease in end-diastolic volume. The percent reduction in end-diastolic volume (% delta EDV) and stroke volume (+ delta SV) from the baseline values was linear and related to change in heart rate (delta HR) as % delta EDV = -0.60 delta HR + 5.19 (r = 0.71; p less than 0.01) and % delta SV = -0.62 delta HR + 5.03 (r = 0.76; p less than 0.001). Left ventricular ejection fraction with baseline sequential A-V pacing at 100 beats/min was 0.67 +/- 0.03 and not significantly altered by either sequential A-V or simultaneous V/A pacing at 160 beats/min. At 100 beats/min, loss of atrial transport with simultaneous V/A pacing resulted in a small reduction in end-diastolic volume from a baseline value of -9.0 +/- 1.9 percent (p less than 0.01) and a nonsignificant reduction in stroke volume of -3.7 +/- 1.6 percent. During simultaneous V/A pacing at 160 beats/min, the reduction in end-diastolic and stroke volumes from the baseline value was -26.6 +/- 3.8 percent and -28.8 +/- 4.3 percent, respectively (both p less than 0.01), but was significantly smaller (-16.1 +/- 3.6 percent and -19.2 +/- 4.1 percent, respectively [p less than 0.05]) when atrial transport was maintained during sequential A-V pacing at the same heart rate. During simultaneous V/A pacing at 160 beats/min, two thirds of the reduction in end-diastolic and stroke volumes from the baseline value was due to the increment in heart rate as assessed from sequential A-V pacing and the other third was due to loss of atrial transport. The data indicate that the hemodynamic consequences of supraventricular tachyarrhythmias in patients with normal ventricular function are due primarily to decreases in ventricular volume as heart rate is increased and atrial contribution is lost rather than to any changes in left ventricular ejection fraction.

Adult↗

The effects of left atrial and left ventricular cannulation on left ventricular function.

A study in anesthetised dogs was undertaken to investigate the immediate effects of cannulation of the heart for left heart bypass on left ventricular function. Twenty-six mongrel dogs were studied. In the first group of 13 dogs (Group A), left atrial cannulation was performed through the atrial appendage and in the second group of 13 dogs (Group B), the left ventricular apex was also cannulated. Systemic blood pressure, heart rate, left atrial pressure, left ventricular end diastolic pressure and dP/dT showed no difference in left ventricular function between Groups A and B. Global ejection fraction (EF) measured by injection of technetium99m-labelled human serum albumen with gated left ventricular imaging, showed no significant difference between the two groups but analysis of the regional contribution to global EF in Group B dogs demonstrated a significant reduction in left ventricular function at the site of ventricular cannulation (P less than 0.05). These findings, together with other reported disadvantages of left ventricular cannulation, suggest that the left atrium is the preferred site for cannulation when left heart bypass is required. Many reports attest to the value of mechanical circulatory support in patients with ventricular dysfunction who cannot be weaned from cardiopulmonary bypass (2, 4, 10, 11, 15). Initial support is commonly provided by an intra-aortic balloon pump but, in more severe cases, use of a left ventricular assist device may be warranted. More recently, such devices have also been employed in the management of patients with cardiogenic shock refractory to medical therapy (10).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Long-term effect of VVI pacing on atrial and ventricular function in patients with sick sinus syndrome.

We conducted a prospective, 6-month echocardiographic study on the effect of VVI pacing on left atrial and ventricular function and dimensions in patients with sick sinus syndrome. Thirty-nine patients (23 women and 16 men, aged 71 +/- 9.2 years; 30 in sinus rhythm and 9 in atrial fibrillation) who had a VVI pacemaker implanted because of sick sinus syndrome were recruited in the study. In 26 patients who presented with and remained in sinus rhythm, paced left ventricular ejection fraction and stroke volume were significantly decreased (71.4% +/- 11.8% to 67.0% +/- 13.6%, and 73.9 +/- 29.0 cm3 to 66.3 +/- 21.1 cm3, respectively, P < 0.001 for both), whereas the paced diastolic dimension of the left atrium was significantly increased (3.2 +/- 0.7 cm to 3.7 +/- 0.9 cm, P < 0.001) at 6 months as compared with preimplantation. In nine patients with atrial fibrillation at implantation paced left ventricular ejection fraction at follow-up was significantly decreased (67.7% +/- 10.1% to 64.2% +/- 10.6%, P =0.003), but paced stroke volume and left atrial diastolic dimension were not significantly changed (75.1 +/- 25.6 cm3 to 79.0 +/- 22.7 cm3, and 4.3 +/- 1.2 cm to 4.6 +/- 1.5 cm, P = NS for both) at follow-up. Cessation of pacing and restoration of sinus rhythm in 21 patients at follow-up did not result in any significant change of ejection fraction (67.5% +/- 10.2% ti 67.6% +/- 9.7%, P = NS) whereas stroke volume was increased (59.1 +/- 19.6 cm3 to 69.1 +/- 22.3 cm3, P < 0.0001) in comparison with paced values. However, compared with preimplantation values, ejection fraction was significantly decreased (70.4% +/- 10.0% to 67.6% +/- 9.7%, P = 0.001), whereas stroke volume was not significantly changed (68.4 +/- 22.3 cm3 to 69.1 +/- 22.3 cm3, P = NS) during sinus rhythm at follow-up. In 14 of those patients, discontinuation of pacing resulted in a significant increase of left atrial fractional shortening (8.1% +/- 1.7% to 20.1% +/- 4.3%, P < 0.001) and significant increase of left atrial diastolic dimension compared with paced and preimplantation levels (3.8 +/- 0.7 cm vs 3.6 +/- 0.7 cm and 3.0 +/- 0.5 cm, respectively, P < 0.001). Long-term VVI pacing in patients with sick sinus syndrome results in increase of the left ventricular end-systolic dimension and permanent reduction of the left ventricular ejection fraction. In the left atrium, VVI pacing causes an immediate reduction of the fractional shortening as well as long-term increase of the diastolic dimension.

Aged↗

Assessment of left ventricular systolic function in patients with chronic atrial fibrillation and dilated cardiomyopathy using the ratio of preceding to prepreceding R-R intervals.

The objective of this study was to determine the relation between left ventricular (LV) systolic function and the ratio of preceding (RR1) to prepreceding (RR2) R-R intervals in patients with chronic atrial fibrillation (AF) and dilated cardiomyopathy. LV systolic function (Emax) was examined using a conductance catheter with a micromanometer in 13 patients with chronic AF and dilated cardiomyopathy. We calculated Emax as a load-independent index of LV contractility and compared it with RR1, RR2, and the ratio of RR1/RR2. We analyzed 50+/-13 cardiac cycles (range 18-61) in each patient. Average heart rate was 80+/-13 beats/min, and ejection fraction over all cardiac cycle in each patient measured by conductance catheter was 31+/-8%. Emax was positively correlated with RR1 and RR1/RR2 in all patients, and negatively correlated with RR2 in all patients. In each patient, correlation coefficients of Emax with RR1/RR2 were greater than those with either RR1 or RR2. Furthermore, Emax at RR1/RR2=1 in the linear regression line reflected average Emax over all cardiac cycles in each patient. In conclusion, we have shown that LV contractility correlated positively with RR1/RR2 in patients with chronic AF and dilated cardiomyopathy, and LV contractility at RR1/RR2=1 represents the average value of contractility over all cardiac cycles.

Adult↗

Extracardiac adjustment of mitral chordae replacement.

This study was designed to determine the feasibility of completing mitral chord repair externally when the heart was weaned from bypass. Ten anesthetized dogs (22.9 +/- 4.6 kg) were placed on cardiopulmonary bypass through a left thoracotomy. The left atrium was opened and one or two marginal chords of the anterior mitral leaflet were divided. A double-armed 2-O polypropylene suture was placed in the margin of the mitral leaflet, and both suture ends were brought outside of the ventricle through the anterior papillary muscle, but were not anchored. Production of mitral incompetence was verified when the animals were weaned from bypass. Mean left atrial pressure (LAPm), the v wave of the left atrial pressure (LAPv), systolic billowing of the anterior leaflet into the left atrium above the mitral closure line (two-dimensional echocardiography, long axis), and function curves (left atrial-aortic systolic pressure, LAPv-AoSP) were used to determine valve competence and functionality of the repair. All values are expressed as means +/- SE. Acute mitral incompetence in this model was associated with severe left atrial bulging, left atrial billowing of the anterior leaflet (7-12 mm, 9.6 +/- 1.6 mm), significantly increased left atrial pressure [LAPv, 30.5 +/- 5.8; LAPm, 23.6 +/- 4.3 mm Hg; both P < 0.01 vs control (10.5 +/- 2.5 and 7.5 +/- 2.7 mm Hg, respectively)], and decreased systemic pressure development (AoSP, 84 +/- 8.8 vs 108 +/- 12.3 mm Hg; P < 0.01). The slope of the atrial-systemic pressure curve was decreased significantly, shifted to the right and reduced by more than half (2.1069 vs 0.9190; P < 0.05). External adjustment of the pledgeted suture ends returned all values to within control limits (LAPv, 12.7 +/- 4.1; LAPm, 9.8 +/- 4.3; AoSP, 104 +/- 10.5; LAP-AoSP slope, 2.0909; all P = n.s.), atrial bulging was not evident, and atrial displacement of the valve leaflet could no longer be visualized. These data suggest that mitral chord repair is feasible through a thoracotomy and, more importantly, final adjustments to obtain optimal chord length can be completed externally, guided by changes in dynamic, physiologic parameters.

Animals↗

Right Atrial Thrombi and Depressed Right Atrial Appendage Function After Cardioversion of Atrial Fibrillation.

BACKGROUND: It has been shown that cardioversion of atrial fibrillation may result in left atrial chamber and appendage dysfunction and cause new thrombi in the left atrium. The aim of this prospective study was to investigate right atrial appendage function and assess the incidence of new right atrial thrombi after electrical cardioversion. METHODS: Transthoracic echocardiography was performed in 25 patients 4 h before and at 24 h and 7 days after electrical cardioversion to determine right and left atrial mechanical function (internal atrial defibrillation, n = 16; external electrical cardioversion, n = 9), as assessed by peak A wave velocities derived from the transtricuspid and transmitral velocity profiles. In addition, transesophageal echocardiography was performed 4 h before and 24 h after cardioversion to evaluate postcardioversion thrombus formation in the right and left atrial chambers and to assess right and left atrial appendage function. The degree of spontaneous echo contrast was noted, and peak emptying velocities of the appendages were measured before and after cardioversion. RESULTS: Peak emptying velocities of both the right atrial appendage (mean +/- SD, 0.23 +/- 0.1 vs 0.32 +/- 0.11 m/sec; P = 0.02) and the left atrial appendage (0.3 +/- 0.15 vs 0.4 +/- 0.15 m/sec; P = 0.01) were significantly lower 24 h after cardioversion compared with 4 h before cardioversion, respectively. The degree of spontaneous echo contrast increased in the left atrium after cardioversion from 1.0 +/- 1.2 to 1.9 +/- 2.1 (P = 0.02), and in the right atrium, it increased from 0.8 +/- 1.1 to 1.2 +/- 1.1 (P = 0.1) after cardioversion. Peak A wave transtricuspid velocity increased from 0.26 +/- 0.05 m/sec at 24 h to 0.38 +/- 0.06 m/sec (P = 0.001) after 7 days; respective values for transmitral peak A wave velocity were 0.39 +/- 0.15 and 0.54 +/- 0.16 m/sec (P = 0.009). No thrombi were found in either the right or left atrium before cardioversion. In two patients, new thrombi in the right atrium were detected 24 h after internal atrial defibrillation. Thrombi were located at the superior rim of the fossa ovalis in both patients with patent foramen ovale. Another patient had developed a thrombus in the left atrial appendage. CONCLUSIONS: Electrical cardioversion may not only cause left atrial chamber and appendage dysfunction and left atrial thrombi but also lead to depressed right atrial appendage function and the generation of new thrombi in the body of the right atrium.

Journal Article↗

Mechanical remodeling of the left atrium after loss of atrioventricular synchrony. A long-term study in humans.

BACKGROUND: Tachycardia-mediated mechanical remodeling of the atrium is considered central to the pathogenesis of thromboembolism associated with chronic atrial fibrillation. Whether atrial mechanical remodeling also occurs in response to atrial stretch induced by chronic asynchronous ventricular pacing in patients with permanent pacemakers is unknown. METHODS AND RESULTS: The study design was a prospective randomized comparison between 21 patients paced chronically in the VVI mode and 11 patients paced chronically in the DDD mode for 3 months. Left atrial appendage (LAA) function and the presence of spontaneous echo contrast (SEC) were determined with transesophageal echocardiography (TEE) within 24 hours of pacemaker implantation and after 3 months. The VVI patients were then programmed to DDD and underwent a third TEE after DDD pacing for an additional 3 months. After chronic VVI pacing, LAA velocity decreased from 82.4+/-29.0 to 42.1+/-25.4 cm/s (P<0.01), LAA fractional area change decreased from 74.9+/-17.2% to 49.8+/-22.0% (P<0.01), and 4 patients (19%) developed left atrial SEC (P<0.05). With the reestablishment of chronic AV synchrony, LAA velocity increased to 61.6+/-18.5 cm/s (P<0.01), LAA fractional area change increased to 76.4+/-18.1% (P<0.01), and SEC resolved. In the 11 patients undergoing chronic DDD pacing, no significant changes in LAA velocity (baseline, 86.0+/-28.8 cm/s versus 3 months, 79.6+/-14. 9 cm/s) or LAA fractional area change (baseline, 76.2+/-19.4% versus 72.5+/-15.7%) were demonstrated, and SEC did not develop. CONCLUSIONS: Chronic loss of AV synchrony induced by VVI pacing is associated with mechanical remodeling of the left atrium, which may reverse after the reestablishment of AV synchrony with DDD pacing. This process may be partly responsible for the higher incidence of thromboembolism observed in patients undergoing VVI pacing compared with AV sequential pacing.

Aged↗

Relation of arterial stiffness to left ventricular diastolic function and cardiovascular risk prediction in patients > or =65 years of age.

There is a paucity of data regarding the relation between the various noninvasive indexes of arterial stiffness and left ventricular diastolic function. In 188 subjects aged > or =65 years (mean 75 +/- 5; 71% men), the concordance and strength of the association between measures of arterial stiffness and left ventricular diastolic function were evaluated. Indexes of arterial stiffness (brachial and aortic pulse pressure [PP], carotid-femoral pulse-wave velocity [PWV], and augmentation pressure [AP]) were measured using applanation tonometry. Diastolic function was classified in terms of instantaneous diastolic function grade and quantitated as left atrial volume, a measure of chronic diastolic burden. Risk for new cardiovascular events was estimated using a validated clinical echocardiographic risk algorithm. Aortic and brachial PP, PWV, and AP were correlated positively with left atrial volume and diastolic function grade. After adjusting for age, gender, and clinical and echocardiographic covariates, 1-SD increases in aortic PP, brachial PP, PWV, and AP were associated with 6%, 6%, 4%, and 4% increases in indexed left atrial volume, respectively. Similarly, 1-SD increases in aortic PP, brachial PP, and AP were associated with 84%, 81%, and 83% increased risk for diastolic dysfunction, respectively (all p <0.04). PWV and aortic and brachial PP were superior to AP in discriminating subjects with the highest risk of having new cardiovascular events (5-year risk >50%; area under receiver-operating characteristic curve 0.67, 0.67, 0.70, and 0.56, respectively; p <0.05). In conclusion, increased arterial stiffness was associated with more severe left ventricular diastolic dysfunction, although the strength of the association varied according to the specific measure used. Aortic PP, brachial PP, and PWV appeared superior to AP in risk discrimination in this elderly cohort.

Aged↗

Clinical application of atrial natriuretic polypeptide in patients with congestive heart failure: beneficial effects on left ventricular function.

Synthetic alpha-human atrial natriuretic polypeptide was infused in patients with congestive heart failure (CHF) (New York Heart Association class III or IV) and in those without CHF. The infusion of atrial natriuretic polypeptide (ANP) at a rate of 0.1 microgram/kg/min significantly decreased pulmonary capillary wedge pressure and increased stroke volume index in all of the patients with CHF, whereas it decreased pulmonary capillary wedge pressure but caused no significant change in stroke volume index in the patients without CHF. Concomitant significant reductions in total systemic resistance were observed in both groups of patients. The ANP infusion significantly increased the urine volume, the excretion of sodium, and endogenous creatinine clearance in the patients without CHF. In the patients with CHF, it also showed a tendency to increase all these variables, but the urine volume did not correlate with the reduction in pulmonary capillary wedge pressure. The ANP infusion also decreased plasma aldosterone concentrations in these patients, although no significant difference was observed in the decrement of the plasma aldosterone concentration in the patients with and those without CHF. These findings indicate that the ANP infusion improves left ventricular function in patients with CHF, and suggest that this improvement results mainly from the vasodilating activity of ANP.

Adult↗

[Functional state of the left regions of the heart in healthy persons during isometric exercise].

Hemodynamic parameters of left and atrial contractile and pump functions were examined in 25 healthy males undergoing leg isometric exercise, by employing echocardiography. Analysis of changes in intracardiac hemodynamics showed that for provision of a marked pressor reaction occurring in healthy persons during isometric exercise, there was enhanced left ventricular myocardial contractility and thereby higher stroke and minute volumes. To maintain the required increase in stroke volume at the maximal exercise level, an accessory mechanism of compensation gears (by the Frank-Starling type), which operates due to myocardial diastolic relaxation, elevated venous blood supply at the expense of sucking cardiac action, and augmented left atrial contractility.

Adult↗

[Left atrial size in patients with arterial hypertension].

INTRODUCTION: Left atrial size is increased in patients with arterial hypertension. Left atrial enlargement represents a risk factor of atrial fibrillation and stroke. Left atrial size depends on the effect of many other etiological factors, predominantly by body mass and the left ventricular mass. OBJECTIVE: The objective of the study was to investigate the frequency of the left atrial enlargement in patients with arterial hypertension, in obese patients with arterial hypertension and in patients with arterial hypertension and left ventricular hypertrophy. In addition, the aim was to investigate the influence of diastolic function parameters on the left atrial dimension. METHOD: The study included 93 patients with arterial hypertension (mean age of 46.9 +/- 9.7 years, 50.5% of males) and 33 healthy subjects (mean age 45.6 +/- 10.6 yrs., 40% of males) who consisted the control group. There was no statistical difference of the age and sex between patients and healthy persons. All patients were examined by the echocardiographic ultrasound device HP Sonos 2500 by three echosonographers. RESULTS: The patients with arterial hypertension compared to the control group had significantly higher: body mass index (27.8 +/- 4.1 versus 24.3 +/- 3.0) (p<0.001), the left ventricular mass (249.7 +/- 79.1 versus 174.6 +/- 47.7) (p<0.001), the left ventricular mass index (122.2 +/- 34.3 versus 96.7 +/- 20.9) (p<0.001) and the left atrium (3.8 +/- 0.7 versus 3.3 +/- 0.5) (p<0.001). The frequency of the left atrial enlargement in patients with arterial hypertension was 44.1%. The frequency of the left atrial enlargement in patients with arterial hypertension and the left ventricular hypertrophy was 53.3%, and in obese patients with arterial hypertension was 58.3%. Left ventricular diastolic function parameters in patients with arterial hypertension in relation to control exhibited statistically significant differences: isovolumetric relaxation time (IVRT) was longer (193.2 +/- 37.8 versus 175.8 +/- 23.6) (p<0.001), deceleration time (DT) was longer (193.2 +/- 37.8 versus 175.8 +/- 23.6) (p<0.01) and peak early diastolic filling wave velocity / peak atrial diastolic filling wave velocity ratio (E/A ratio) was lower (1.0 +/- 0.3 versus 1.2 +/- 0.3) (p<0.01). The quotient of linear correlation of the left ventricular diastolic function parameters in patients with arterial hypertension with left atrial volume did not show any significant correlation. CONCLUSION: The left atrial size was statistically bigger in patients with arterial hypertension in relation to healthy subjects. The biggest left atrial enlargement was in hypertensive patients with the left ventricular hypertrophy and obese hypertensive patients. Left ventricular diastolic function parameters in patients with arterial hypertension had no statistically significant influence on the left atrial size.

Body Mass Index↗

Factors associated with the development of atrial fibrillation in COPD patients: the role of P-wave dispersion.

BACKGROUND: Supraventricular tachyarrhythmia is a common problem in chronic obstructive pulmonary disease (COPD) patients. The purpose of this study is to analyze the factors associated with paroxysmal atrial fibrillation (AF) in COPD patients. METHODS: Forty COPD patients (38 male, 2 female, mean age 60 +/- 9 years) and 33 healthy controls (29 male, 4 female, mean age: 58 +/- 10 years) were included in this study. Echocardiography, 24-hour ambulatory and 12-lead ECG, pulmonary function tests, arterial blood gases, and serum electrolytes were measured. On ECG, maximum (P(max)) and minimum (P(min)) duration of P wave and its difference, P-wave dispersion (PWd), were measured. RESULTS: On echocardiography, diastolic dysfunction was found in 14 of the 40 (35%) COPD patients. Heart rate variability analysis revealed that COPD patients had decreased SDANN, SDNN, SDNNIDX in time-domain, and decreased LF in frequency domain parameters. Fourteen of the 40 COPD patients (35%) had AF. Patients with AF were older (57 +/- 10 vs 64 +/- 5 years, P = 0.03) and had lower SDANN, SDNN, and LF/HF ratio as compared to patients without AF in univariate analysis. All P-wave intervals (P(max), P(min,) and PWd) were increased in COPD patients compared to controls. P-wave dispersion was significantly increased in COPD patients with AF, as compared to patients without AF (57 +/- 11 vs 44 +/- 7 ms, P = 0.001). In logistic regression analysis PWd was found to be the only factor associated with the development of AF (P = 0.04). CONCLUSIONS: The presence of AF was significantly related to the prolongation of PWd, but not with pulmonary function, arterial blood gasses, and left and right atrial function.

Age Distribution↗

[Flow in pulmonary veins].

Pulmonary venous flow can be evaluated by means of pulsed Doppler echocardiography during a transthoracic or transesophageal echocardiography examination. In most cases a three-peak spectral curve with highest positive wave during ventricular systole, a lower positive wave during ventricular diastole and a small negative wave during the left atrial contraction are recorded. Multiple factors affect the systolic and diastolic components of pulmonary venous flow. Pulmonary venous flow measurement may prove to be an important tool in routine judgment of diastolic left ventricular and atrial function. With regard to clinical importance, the pulmonary venous flow is a useful parameter for left atrial pressure quantification and for differential diagnosis of restrictive cardiomyopathy and constrictive pericarditis.

Blood Flow Velocity↗

Left atrial afterload mismatch in hypertrophic cardiomyopathy.

To investigate left atrial (LA) booster pump function in hypertrophic cardiomyopathy (HC), LA and left ventricular pressure-volume loops were estimated in 5 control subjects, 6 patients with essential hypertension and 11 patients with HC. Investigation of LA preload revealed that LA pressure and volume immediately before LA contraction were both increased in patients with hypertension (10 +/- 5 mm Hg, 71 +/- 19 ml/m2) compared with control subjects (7 +/- 1 mm Hg, 59 +/- 6 ml/m2), and even more increased in patients with HC (16 +/- 7 mm Hg, 81 +/- 25 ml/m2). Investigation of LA afterload revealed that the left ventricular chamber stiffness constant was higher in patients with hypertension (0.035 +/- 0.015) than in control subjects (0.028 +/- 0.009), and even more increased in patients with HC (0.056 +/- 0.017). LA stroke work index was higher in patients with hypertension (116 +/- 34 mm Hg.ml) and HC (115 +/- 19 mm Hg.ml) than in control subjects (87 +/- 23 mm Hg.ml). Investigation of LA ejection revealed that LA stroke index was higher in patients with hypertension (24 +/- 5 ml/m2) than in control subjects (18 +/- 4 ml/m2) and patients with HC (18 +/- 2 ml/m2), and LA ejection fraction was lower in patients with HC (23 +/- 6%) than in control subjects (32 +/- 7%) and patients with hypertension (34 +/- 8%). In patients with HC, LA function curve showed a shift to the lower right, and LA stroke index was inversely correlated (r = -0.76) with LA afterload. This study suggests that LA booster pump failure due to LA afterload mismatch exists in HC.

Adult↗

Serial changes of left atrial thrombus in mitral stenosis: transesophageal echocardiographic studies in candidates for balloon mitral commissurotomy.

BACKGROUND: Little is known concerning therapeutic modification of left atrial thrombus in mitral stenosis and its formation after successful balloon valvuloplasty (percutaneous transvenous mitral commissurotomy [PTMC]). OBJECTIVE: To test the roles of the clinical use of anticoagulant therapy and PTMC, serial changes in left atrial thrombus were examined by transesophageal echocardiography in 80 patients with mitral stenosis. RESULTS: No difference in embolic history, New York Heart Association functional class, cardiac rhythm, left atrial size or mitral valve area was found between patients with (n=23) and without (n=57) left atrial thrombus. Diuretic use was the prevalent factor for left atrial thrombi, which were dissolved completely in seven (30.4%) and partially in eight (34.7%) of the patients by adequate warfarin. However, after PTMC (n=53), newly formed thrombus was observed in four of 51 (7.8%) patients, which correlated with left atrial size (at least 50mm), atrial fibrillation and poorly controlled warfarin (thrombo test: 63.8 +/- 18.8% versus 35.9 +/- 17.7%, P<0.005). The newly formed thrombi were dissolved within several weeks. CONCLUSION: Left atrial thrombus in symptomatic mitral stenosis exhibits elusive characteristics and should be strictly monitored even after successful PTMC by transesophageal echocardiography in order to achieve adequate anticoagulation.

Atrial Function, Left↗

Left atrial emptying fraction correlation with vascular pedicle width in patients with normal systolic function.

OBJECTIVE: To determine the correlation and diagnostic utility of impaired left atrial emptying fraction, an indicator of diastolic dysfunction, with raised intravascular volume determined by vascular pedicle width on upright postero-anterior chest roentgenogram. DESIGN: Cohort study. PLACE AND DURATION OF STUDY: Department of Medicine, King Abdulaziz National Guard Hospital, Alhasa, Saudi Arabia from October till December 2002. PATIENTS AND METHODS: Thirty-two out of 56 patients with normal systolic function (ejection fraction >50%) on echocardiogram were included in the study. Left atrial dimensions were measured at the end of left ventricular diastole (LADed) and systole (LADes) on M-mode tracing. Left atrial emptying fraction (LAEF) was calculated by dividing LADed by LADes. Ratio of peak early diastolic velocity (E/A) to peak late diastolic velocity, isovolemic relaxation time (IVRT) and deceleration time of E-wave (DT) were also recorded on transmitral Doppler signal. Postero-anterior views of chest X-rays done within 48 hours of echocardiogram were studied for the measurement of vascular pedicle width (VPW) and cardiothoracic ratio (CTR). Univariate and multiple regression analysis were performed to identify possible predictors of VPW. Receiver operator curves were constructed to see diagnostic utility of impaired LAEF for raised intravascular volume measured by VPW. RESULTS: Mean age for the patients was 58.56 +/- 17 years. There were 15 females (46.9%) and 17 males (54.1%). LADes, LADed, LAEF and DT were 2.89 +/- 0.63 cm, 3.81 +/- 0.53 cm, 0.75 +/- 0.10 and 202 +/- 49.9 msec respectively. VPW and CTR were 55.81 +/- 10.2 mm and 0.54 +/- 0.08. Significant independent predictors of VPW on univariate regression analysis were entered into multiple regression models, which revealed LAEF and DT as the only predictors of VPW. The final regression equation was VPW = 15.43 + 35.7 (LAEF) + 0.06 (DT), R2 = 0.35, p = 0.0008. LAEF > 0.75 had a sensitivity of 74% and specificity of 94% for diagnosing raised intravascular volume defined as VPW > 53 mm. CONCLUSION: LAEF > 0.75 is a reliable indicator of intravascular volume expansion in patients with normal systolic function signifying diastolic dysfunction and activation of salt and water retaining mechanisms.

Atrial Function, Left↗

[Occurrence of persistent atrial fibrillation in acquired heart defects].

Functional relationship between hemodynamic overstrain and left-atrial distension was investigated in 209 patients with acquired heart diseases and developing persistent atrial fibrillation. The development of constant atrial fibrillation was shown to depend on the correlation between mean left-atrial pressure and size, and functional relations between the two parameters, i. e. their critical ratio at the time when constant fibrillation is established, were determined. The critical curves which define this relationship for males and females demonstrate that constant fibrillation develops in patients with high mean pressure in the left atrium that is only slightly distended, and in patients with lower mean pressure in a considerably distended left atrium.

Adolescent↗