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PubMed2004

Relation between left ventricular contractile reserve during low dose dobutamine echocardiography and plasma concentrations of natriuretic peptides.

BACKGROUND: In ischaemic cardiomyopathy, raised plasma concentrations of natriuretic peptides are associated with a poor long term prognosis, while the presence of contractile reserve is a favourable sign. OBJECTIVE: To assess the relation between plasma natriuretic peptides and contractile reserve. DESIGN: Prospective observational study. SETTING: Tertiary referral centre. PATIENTS: 66 consecutive patients undergoing low dose dobutamine stress echocardiography to evaluate contractile reserve in regions with contractile dysfunction at rest, divided into two groups: group 1, 31 patients with ischaemic cardiomyopathy (left ventricular ejection fraction < or = 40%) and heart failure symptoms; group 2, 35 patients with normal left ventricular function. MAIN OUTCOME MEASURES: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), measured using immunoradiometric assays. Contractile reserve was defined as an improvement in segmental wall motion score during infusion of low dose dobutamine. RESULTS: Plasma ANP and BNP concentrations were higher in group 1 than in group 2 (mean (SD): ANP, 17.8 (32.8) v 7.2 (9.7), p < 0.005; BNP, 24.4 (69.0) v 5.0 (14.3) pmol/l, respectively; p < 0.001). In group 1, the presence of contractile reserve was inversely related to ANP and BNP levels; however, patients with contractile reserve had lower ANP and BNP concentrations than patients without contractile reserve (ANP, 14.2 (9.1) v 24.2 (44.2), p < 0.05; BNP, 20.2 (25.5) v 37.5 (93.8) pmol/l, respectively; p < 0.05). CONCLUSIONS: Plasma natriuretic peptide concentrations are raised in patients with left ventricular dysfunction, but in the presence of preserved myocardial contractile reserve, relatively low levels of ANP and BNP are present.

Echocardiography, Stress↗
PubMed1978

Effect of acute blood volume expansion on cardiac output, plasma dopamine beta-hydroxylase, and renal function in rats with chronic constriction of the ascending aorta.

To examine the effect of raised left atrial pressure (AP) on the relationship of cardiac output to renal function, we constricted the ascending aorta in rats (AC) and 1-6 months later tested their response to acute volume expansion (VE) with blood (2% body weight, iv). Sham-operated (SH) rats were controls. In AC rats heart weight increased 38%, but cardiac output was 47% lower. Statistically significant differences in the initial clearance periods were (AC vs. SH): venous pressure (VP) 8 +/- 2 vs. 3+/- 1 cm H2O; inulin clearance (CIN) 0.61 +/- 0.06 vs. 0.84 +/- 0.04 ml/min; sodium excretion (UNAV) 1.2 +/- 0.2 vs. 2.1 +/- 0.3 muequiv./min. Filtration fraction, fractional UNaV, mean arterial pressure (MAP), and plasma dopamine beta-hydroxylase (DBH) were the same in both groups. After VE, cardiac output increased proportionately more in AC (69% vs. 27%); however, the absolute increases were not different. UNaV increased proportionately more in AC rats, but the absolute increase was less (5.1 vs. 7.5 muequiv./min). Multiple variable regression analysis showed that UNaV correlated with CIN, MAP, and VP, with no difference between AC and SH animals. Cardiovascular-renal relationships were indistinguishable from previous descriptions of dogs and rats with chronic vena caval constriction. Modulation of renal function by left AP was not apparent. In both groups after the peak response to VE, UNaV decreased in association with decreased cardiac output and increased sympathetic nervous activity as indicated by raised DBH levels. After VE, VP remained high in AC but not in SH animals.

Animals↗
PubMed2001

Maternal diastolic function in asymptomatic pregnant women with bilateral notching of the uterine artery waveform at 24 weeks' gestation: a pilot study.

OBJECTIVE: To study second-trimester maternal cardiac adaptation in asymptomatic patients at risk, on the basis of abnormal uterine artery Doppler, for the development of gestational hypertension or having a small-for-gestational age fetus. Fetal and maternal outcomes were verified at the end of pregnancy. METHODS: Thirty-six normotensive women with abnormal uterine artery waveforms underwent maternal echocardiographic examination at 24 weeks' gestation. RESULTS: Twenty-one women (58.3%) subsequently showed normal outcome; 12 patients developed gestational hypertension (33.3%) and three (8.3%) had small-for-gestational age newborns. Left ventricular outflow tract, left ventricular diastolic dimensions and atrial and ventricular function were significantly lower in the pathological outcome group. Diastolic function parameters were significantly different between the two groups: peak mitral E-wave and A-wave and A-wave duration showed lower values in the pathological outcome group. Isovolumetric relaxation time of the left ventricle was significantly longer in the pathological outcome group. The prevalence of an altered geometric pattern was 14.3% (3/21) in the normal and 80% (12/15) in the pathological outcome groups (P < 0.001). CONCLUSIONS: Women who subsequently develop a complication of pregnancy tend to display abnormal cardiac adaptation. An abnormal placentation process, expressed by an elevated resistance index and the presence of notches in the uterine artery waveform, are likely to cause an adaptative mechanism involving the whole cardiovascular system. A pathological outcome of pregnancy is associated with the failure of this process.

Adult↗
PubMed1980

Favorable effects of oral digoxin therapy on the left ventricular performance in patients with artificial pacemakers.

The contribution of atrial systole in the left ventricular (LV) function and the effects of oral digoxin maintenance therapy on the LV function were evaluated noninvasively in patients who had artificial pacemakers but no clinical manifestation of congestive heart failure (NYHA Class I). Diastolic dimension (Dd), ejection time (ET), and stroke volume were constant in 8 patients without P waves on their electrocardiograms, but in 20 patients with P waves they were variable from beat to beat because of the variation of the PR intervals which caused them to reach their maximum values when the PR intervals were 160 to 200 msec. Ten out of the 28 patients were given 0.25 mg of digoxin daily for 10 days. Dd did not change significantly, but the ET and the systolic dimension were significantly shortened (P < 0.001). Posterior wall excursion, ejection fraction, and mean posterior wall velocity were significantly increased (P < 0.001). It is concluded that (1) atrial contraction is important to the LV function in patients with artificial pacemakers, and (2) that favorable effects on the LV function can be obtained by a small dose of digoxin administered to the patients who had artificial pacemakers but no congestive heart failure.

Adult↗
PubMed1999

Dofetilide in patients with congestive heart failure and left ventricular dysfunction. Danish Investigations of Arrhythmia and Mortality on Dofetilide Study Group.

BACKGROUND: Atrial fibrillation occurs frequently in patients with congestive heart failure and commonly results in clinical deterioration and hospitalization. Sinus rhythm may be maintained with antiarrhythmic drugs, but some of these drugs increase the risk of death. METHODS: We studied 1518 patients with symptomatic congestive heart failure and severe left ventricular dysfunction at 34 Danish hospitals. We randomly assigned 762 patients to receive dofetilide, a novel class III antiarrhythmic agent, and 756 to receive placebo in a double-blind study. Treatment was initiated in the hospital and included three days of cardiac monitoring and dose adjustment. The primary end point was death from any cause. RESULTS: During a median follow-up of 18 months, 311 patients in the dofetilide group (41 percent) and 317 patients in the placebo group (42 percent) died (hazard ratio, 0.95; 95 percent confidence interval, 0.81 to 1.11). Treatment with dofetilide significantly reduced the risk of hospitalization for worsening congestive heart failure (risk ratio, 0.75; 95 percent confidence interval, 0.63 to 0.89). Dofetilide was effective in converting atrial fibrillation to sinus rhythm. After one month, 22 of 190 patients with atrial fibrillation at base line (12 percent) had sinus rhythm restored with dofetilide, as compared with only 3 of 201 patients (1 percent) given placebo. Once sinus rhythm was restored, dofetilide was significantly more effective than placebo in maintaining sinus rhythm (hazard ratio for the recurrence of atrial fibrillation, 0.35; 95 percent confidence interval, 0.22 to 0.57; P<0.001). There were 25 cases of torsade de pointes in the dofetilide group (3.3 percent) as compared with none in the placebo group. CONCLUSIONS: In patients with congestive heart failure and reduced left ventricular function, dofetilide was effective in converting atrial fibrillation, preventing its recurrence, and reducing the risk of hospitalization for worsening heart failure. Dofetilide had no effect on mortality.

Adult↗
PubMed1995

Doppler reconstruction of left ventricular pressure from functional mitral regurgitation: potential importance of varying orifice geometry.

OBJECTIVE: To assess the left ventricular pressure pulse, in particular its time course, reconstructed from the continuous wave Doppler signal of functional mitral regurgitation using the simplified Bernoulli equation. DESIGN: Prospective study with simultaneously recorded high fidelity left ventricular pressure and continuous wave Doppler traces of functional mitral regurgitation, along with indirect left atrial pressure, electrocardiograms, and phonocardiograms. SETTING: Tertiary referral cardiac centre. PATIENTS: 9 patients (age 60 (17) years) were studied immediately before or 1-20 h after routine cardiac surgery. RESULTS: 104 cardiac cycles were analysed. There were no consistent differences between directly measured and reconstructed pressures in the time intervals from Q to + dP/dt (mean (SD) 125 (35) v 130 (35) ms and from Q to -dP/dt (389 (30) v 387 (28) ms or from Q to maximum pressure (267 (40) v 270 (40) ms, all P = NS). The time from Q to the onset of pressure rise (67 (30) v 64 (30) ms, P < 0.01) and the duration of total left ventricular systole (404 (50) v 408 (50) ms, P < 0.01) measured by the two methods were effectively identical, though the small difference was consistent enough to be statistically significant. The calculated peak pressure drop between the left ventricle and the left atrium (45-100 mm Hg) significantly underestimated left ventricular pressure (72-150 mm Hg; 70 (11) v 105 (15) mm Hg, P < 0.01) even if mean left atrial pressure (14 (4.0) mm Hg) was taken into account. Compared with those directly derived from left ventricular pressure, values of pressure measured at + dP/dt (26 (6.5) v 53 (10) mm Hg, P < 0.01) and -dP/dt (30 (8.0) v 60 (10) mm Hg, P < 0.01), and those of the rates of increase (675 (155) v 815 (155) mm Hg/s, P < 0.01) and fall (610 (145) v 845 (175) mm Hg, P < 0.01) were all significantly underestimated by Doppler. The underestimation in peak rates of pressure change could not entirely be explained by a scaling effect of absolute pressure. To investigate interrelations between the two methods throughout the cardiac cycle, reconstructed left ventricular pressure was plotted against the direct record. The plots confirmed that the reconstructed pressure was always less than directly measured pressure, the relative degree of underestimation falling as the pressure rose. This was not the effect of acceleration but probably reflects changing geometry of the regurgitant orifice. CONCLUSION: The continuous wave Doppler trace of functional mitral regurgitation is suitable for studying the timing of overall mechanical events and normalised rates of change of pressure in the left ventricle. Estimates of atrioventricular pressure drop by this method and particularly its absolute rates of change seem to be less reliable.

Adult↗
PubMed1997

Determinants of pulmonary hypertension in left ventricular dysfunction.

OBJECTIVES: This study sought to analyze the determinants of pulmonary hypertension in patients with left ventricular dysfunction. BACKGROUND: Pulmonary hypertension in patients with left ventricular dysfunction is a predictor of poor outcome. The independent role of cardiac functional abnormalities in the genesis of pulmonary hypertension is unclear. METHODS: In 102 consecutive patients with primary left ventricular dysfunction (ejection fraction < 50%), systolic pulmonary artery pressure was prospectively measured by Doppler echocardiography (using tricuspid regurgitant velocity), and left ventricular systolic and diastolic function, functional mitral regurgitation, cardiac output and left atrial volume were quantified. RESULTS: Systolic pulmonary artery pressure was elevated in patients with left ventricular dysfunction (51 +/- 14 mm Hg [mean +/- SD]), but the range was wide (23 to 87 mm Hg). Of the numerous variables correlating significantly with systolic pulmonary artery pressure, the strongest were mitral deceleration time (r = -0.61, p = 0.0001; odds ratio of pulmonary pressure > or = 50 mm Hg [95% confidence interval] if < 150 ms, 48.8 [14.8 to 161]) and mitral effective regurgitant orifice (r = 0.50, p = 0.0001; odds ratio [95% confidence interval] if > or = 20 mm2, 5.9 [2.3 to 15.5]). In multivariate analysis, these two variables were the strongest predictors of systolic pulmonary artery pressure in association with age (p = 0.005). Ejection fraction or end-systolic volume was not an independent predictor of pulmonary artery pressure. CONCLUSIONS: Pulmonary hypertension is frequent and highly variable in patients with left ventricular dysfunction. It is not independently related to the degree of left ventricular systolic dysfunction but is strongly associated with diastolic dysfunction (shorter mitral deceleration time) and the degree of functional mitral regurgitation (larger effective regurgitant orifice). These results emphasize the importance of assessing diastolic function and quantifying mitral regurgitation in patients with left ventricular dysfunction.

Aged↗
PubMed2004

[Risk assessment in acute myocardial infarction].

Despite the appearance in clinical practice of modern treatment modes as thrombolysis and percutaneous coronary intervention, in-hospital mortality from acute myocardial infarction remains an important problem. In this paper we review recently published data concerning risk stratification in the acute phase of myocardial infarction, different factors affecting the prognosis, their dynamics in the course of the disease, and inter-factor relations. We emphasize the prognostic value of three factors: heart rate variability, left ventricular dysfunction and arrhythmias. Changes in heart rate variability are discussed in association to location of myocardial infarction, patency of infarct-related artery, the chosen treatment mode and its timing. Left ventricular diastolic function and right ventricular function are shown to be predictors of morbidity and mortality after myocardial infarction besides left ventricular systolic function. We also present the latest data concerning the prognostic implication of arrhythmias, their relation to left ventricular function and autonomic nervous system balance. Atrial fibrillation and atrial flutter appear to be important factors in predicting mortality after myocardial infarction, especially in the elderly, as well as ventricular arrhythmias - sustained ventricular tachycardia and ventricular fibrillation.

Aged↗
PubMed2003

Spontaneous conversion of patients with atrial fibrillation scheduled for electrical cardioversion: an ACUTE trial ancillary study.

OBJECTIVES: This study was designed to determine the characteristics and outcomes of spontaneous conversion (SC) to sinus rhythm (SR) in patients with atrial fibrillation (AF) of more than two days. BACKGROUND: The Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) multicenter study was a prospective trial in which transesophageal echocardiography (TEE)-guided treatment was compared with conventional anticoagulation treatment for the management of patients with AF >2 days undergoing direct current cardioversion (DCC). In an ancillary analysis, we evaluated the baseline and outcome data in patients who underwent SC to SR before scheduled DCC. METHODS: We identified 1,041 patients for this analysis after excluding patients on pre-existing antiarrhythmic agents. Patients with SC in the TEE-guided and conventional groups were first compared then pooled and compared with non-spontaneous conversion (No-SC) patients. RESULTS: Overall, 167 of 1,041 (16%) patients underwent SC, with twice as many in the conventional compared with the TEE-guided group (110/523 [21%] vs. 57/518 [11%]; p < 0.001). When compared with No-SC patients, a higher proportion of SC patients maintained SR at eight weeks (87.2% vs. 48.9%, p < 0.001), without statistically significant differences in bleeding, thromboembolism or mortality. Multivariate predictors of SC were shorter duration of AF, New York Heart Association (NYHA) functional class 1 or 2, smaller left atrial size, and absence of left atrial spontaneous echo contrast. CONCLUSIONS: Spontaneous conversion was associated with shorter duration of AF, lower NYHA class, smaller left atrial size, and absence of left atrial spontaneous echo contrast. There was a better SR outcome in the SR group, but no differences in the other clinical end points. The conventional treatment strategy allowed greater opportunity for SC. In the absence of favorable predictors of SC, the TEE-guided approach should be considered.

Atrial Fibrillation↗
PubMed1996

Effect of isolated left atrial enlargement on mitral annular size and valve competence.

Effect of isolated left atrial enlargement on mitral annular size and valve competence was evaluated in 62 patients with normal left ventricular size and function and intrinsically normal mitral leaflets. Echocardiographic data showed that isolated left atrial enlargement could cause enlargement of the mitral annulus and cause mitral regurgitation.

Adult↗
PubMed2005

Left atrial radiofrequency ablation during mitral valve surgery for continuous atrial fibrillation: a randomized controlled trial.

CONTEXT: Although left atrial radiofrequency ablation (RFA) is increasingly used for the treatment of chronic atrial fibrillation during mitral valve surgery, its efficacy to restore sinus rhythm and any resulting benefits have not been examined in the context of an adequately powered randomized trial. OBJECTIVE: To determine whether intraoperative RFA of the left atrium increases the long-term restoration of sinus rhythm and improves exercise capacity. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind trial performed in a single UK tertiary referral center with enrollment between December 2001 and November 2003. A total of 101 patients referred for mitral valve surgery with at least 6 months' history of uninterrupted atrial fibrillation were assessed for eligibility; 97 were enrolled. Patients were followed up for 12 months. INTERVENTION: Patients were randomly assigned to undergo mitral valve surgery and RFA of the left atrium (n = 49) or mitral valve surgery alone (controls; n = 48). MAIN OUTCOME MEASURES: The primary outcome measure was presence of sinus rhythm at 12 months; secondary measures were patient functional status and exercise capacity (assessed by shuttle-walk test), left atrial contractility, and left atrial and left ventricular dimension and function and plasma levels of B-type natriuretic peptide. RESULTS: At 12 months, sinus rhythm was present in 20 (44.4%) of 45 RFA patients and in 2 (4.5%) of 44 controls (rate ratio, 9.8; 95% CI, 2.4-86.3; P<.001). Restoration of sinus rhythm in the RFA group was accompanied by a greater improvement in mean (SD) shuttle-walk distance compared with controls (+94 [102] m vs +48 [82] m; P = .003) and a greater reduction in the plasma level of B-type natriuretic peptide (-104 [87] fmol/mL vs -51 [82] fmol/mL; P = .03). Patients randomized to receive RFA had similar rates of postoperative complications and deaths as control patients. CONCLUSIONS: Radiofrequency ablation of the left atrium during mitral valve surgery for continuous atrial fibrillation significantly increases the rate of sinus rhythm restoration 1 year postoperatively, improving patient exercise capacity. On the basis of its efficacy and safety, routine use of RFA of the left atrium during mitral valve surgery may be justified. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00238706.

Aged↗
PubMed2004

[Pharmacological versus invasive treatment in patients with atrial fibrillation].

Aim of this prospective study was to assess quality of life (QoL), left ventricular (LV) function and exercise performance in two groups of patients (pts) with atrial fibrillation (Af) treated with: radiofrequency catheter ablation (RFA) and antiarrhythmic drugs (AA). Between 1996 and 2000 - 74 patients, 28 women, with drug refractory Af were enrolled by clinical indications for two modes of therapy: RFA and AA. RFA group consisted of 38 pts, 63.7 +/- 11.5 years old: 28 pts with RF AV Node ablation and pacemaker implantation (PI) and 10 pts with AV Node modification or right atrial isthmus RF ablation due to Af conversion to atrial flutter (Aflu) during medical therapy. AA group consisted of 36 pts, aged 59.7 +/- 13.8 years. Patients from RFA group suffered significantly more serious diseases than pts from AA group. No significant (sign.) differences between two groups were found in age, gender, arrhythmia history and number of AA taken. Pts were analyzed before entry, after 3 and 12 months of follow-up (3 mo. FU, 12 mo. FU) with following indices: LV function (Echo: EF & FS), exercise performance (treadmill test), QoL questionnaires, number of hospital admissions connected to arrhythmia or procedures (RFA & PI), number of AA drugs taken in RFA group. RFA group: Two deaths occurred due to end stage respiratory insufficiency (COPD), one pt required reposition of pacemaker lead. AA group: 3 pts required RFA due to uncontrolled Af/Aflu (AV Node ablation with PI - 1 pt, right atrial isthmus ablation - 2 pts). Analysis of two patients groups: LV function: Sign. improvement (EF & FS) in both groups in 12 mo. FU; Exercise performance: no sign. changes in 3 and 12 mo. FU. QoL: Arrhythmia scale: 3 mo. FU sign. reduction in both groups; 12 mo. FU reduction in RFA group only; Anxiety scale: 3 and 12 mo. FU sign. reduction of anxiety level in RFA group; Exercise and activity scales: 3 and 12 mo. FU sign. improvement in RFA group. During 3 and 12 mo. FU sign. less pts from RFA group required hospital admission versus pts from AA group. Sign. reduction in AA was noted in RFA group. Patients with symptomatic Af treated with RFA benefit from this kind of therapy more than patients treated with AA. Quality of life improvement visible in short term observation in patients from RFA group is still present after one year observation. Improvement in LV function is observed after one year in both groups of pts with Af.

Adult↗
PubMed2001

[Processes of left atrial remodeling in myocardial infarction survivors as shown by esophageal rheography].

To study the condition of the left atrium (LA) in patients with myocardial infarction (MI), 112 MI patients were compared to 24 healthy controls by the data obtained at ultrasonic investigation of the heart and esophageal rheography. 73.2% of the patients early after MI showed dilated LA. There were also changes in the ascending part of the rheographic atrial wave at its registration from the esophagus. Its marked prolongation (> 40% of the duration of the whole LA systole) is associated with alterations in the myocardial wall tonicity. If the above value was less, the number of supraventricular extrasystoles significantly increased, episodes of cardiac fibrillation occurred. Changed tonicity of the LA wall was accompanied also with prominent prolongation of the electrophysiological parameters of transesophageal pacing characterizing pacemaker's function and atrioventricular conduction. This suggests involvement not only left but also right atrium. Conclusion is that LA tonicity in MI is damaged and can be studied with esophageal rheography.

Adult↗
PubMed1995

Infarct salvage with liposomal prostaglandin E1 administered by intravenous bolus immediately before reperfusion in a canine infarction-reperfusion model.

BACKGROUND: Prostaglandin E1 (PGE1) inhibits leukocyte and platelet function and reduces infarct size during left atrial infusion. Intravenous liposomal PGE1 (TLC C-53) accelerates thrombolysis and prevents reocclusion in canine coronary thrombosis. We tested the hypothesis that intravenous TLC C-53 would attenuate reperfusion injury in a canine infarction-reperfusion model. METHODS AND RESULTS: Twenty-one open-chest dogs were randomized to receive a 10-minute intravenous infusion of either liposome diluent (placebo), free PGE1 (2 micrograms/kg), or TLC C-53 (2 micrograms/kg PGE1) after 2 hours of left anterior descending (LAD) occlusion just before reperfusion. Hemodynamic assessment, regional myocardial blood flow determination with radioactive microspheres, myocardial leukocyte infiltration by myeloperoxidase assay, and estimation of infarct size using triphenyl tetrazolium chloride staining were performed. Regional fractional shortening was measured with sonomicrometer crystals implanted in the midmyocardium. Infarct size as a percentage of the risk region was significantly reduced (P < .05) with TLC C-53 (37.9 +/- 17.4%) compared with PGE1 (56.7 +/- 13.9%) or placebo (58.0 +/- 9.9%) infusion. Infarct salvage with TLC C-53 was independent of collateral blood flow by ANCOVA. There was a dramatic reduction in myeloperoxidase activity in the infarct, risk, and border regions of dogs treated with TLC C-53 compared with placebo. Enzyme activity was also significantly reduced (P < .05) in the infarct zone with TLC C-53 (0.11 +/- 0.1 U/100 mg) treatment compared with PGE1 (0.38 +/- 0.3 U/100 mg). No significant differences in regional myocardial blood flow or myocardial function among treatment groups were identified, although there was a trend toward improved function in the TLC C-53 dogs. CONCLUSIONS: Bolus intravenous administration of TLC C-53 immediately before reperfusion results in reduced leukocyte infiltration and substantial infarct salvage. TLC C-53 mah be useful in limiting reperfusion injury during treatment of acute myocardial infarction.

Alprostadil↗
PubMed2004

Effects of cardiac resynchronization therapy on disease progression in patients with congestive heart failure.

BACKGROUND: Cardiac resynchronization therapy (CRT) represents a new therapeutic modality of proven efficacy for selected patients with heart failure and ventricular asynchrony. The aim of this study was to assess the effects of CRT on clinical variables and cardiac remodeling in patients with moderate-to-severe congestive heart failure and inter/intraventricular conduction delays. METHODS: Thirty-seven patients (32 males, 5 females, mean age 73 +/- 7 years), in NYHA functional class III-IV, with left ventricular ejection fraction (LVEF) < or = 35%, QRS > or = 150 ms, and left ventricular end-diastolic diameter (LVEDD) > or = 55 mm, underwent CRT by biventricular pacing (InSync, InSync III, InSync ICD; Medtronic Inc.). Fourteen (37.8%) had a previous pacemaker, and 11 (29.7%) were in permanent atrial fibrillation. The QRS width, NYHA functional class, LVEDD, left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic volume (LVEDV), left ventricular endsystolic volume (LVESV), and LVEF were retrospectively evaluated in the period before CRT. For the purposes of the present study, the pre-CRT period was divided in two: T(-2) (from 6 to 3 years) and T(-1) (from 3 years to CRT). Moreover, these parameters were measured at the time of CRT (T0) and prospectively in the post-CRT follow-up (Tp). RESULTS: Before CRT, a progressive worsening of the parameters was observed. The QRS duration steadily increased from T(-2) to T(-1) and T0 (both p = 0.000). The NYHA functional class increased from T(-2) to T(-1) and T0 (both p = 0.000). LVEDD and LVESD also increased and were higher at T(-1) (p = 0.001 and p = 0.000, respectively) and at T0 (both p = 0.000) compared to T(-2). Similar results were observed for LVEDV and LVESV. Finally, LVEF was higher at T(-2) than T(-1) and T0 (both p = 0.000). After CRT, there was a reduction in the QRS duration and an improvement in the NYHA functional class compared to T0 (both p = 0.000). LVEDD and LVESD were also reduced (p = 0.005 and p = 0.016, respectively), LVEDV and LVESV decreased (both p = 0.000), and LVEF increased (p = 0.000) with respect to T0. A highly significant correlation was found between LVEDD and LVESD both in the pre- and post-CRT time intervals, with a non-significant difference between the two linear regression lines. Similar results were obtained for the correlations between LVEDV and LVESV. CONCLUSIONS: Congestive heart failure is associated with a progressive widening of the QRS complex and a worsening of the clinical status and results in anatomic remodeling with deterioration of the left ventricular function. CRT induces opposite changes in QRS duration, clinical status, and left ventricular remodelling.

Aged↗
PubMedDate not supplied

Left ventricular relaxation time index and left atrial emptying index as early echocardiographic indicators in predicting hypertensive heart disease.

To study the earliest changes in left ventricular structure and function appearing in response to hypertensive heart disease the study was started with an initial group of subjects detected for the first time in their lives with elevated levels of systemic blood pressures. A careful follow up of these subjects during the next year allowed the division of these subjects into a group of healthy not hypertensive subjects and a group of subjects with mild essential systemic hypertension detected in an early phase. The next six years of repeated controls (arterial blood pressure measurement, clinical examination, routine chest X-ray pictures, standard 12 leads ECG and M-mode echocardiography) allowed a further division of the hypertensive subjects into two groups of patients: one correctly treated and the other treated incorrectly or not at all. It was found that left ventricular diastolic functions expressed by left ventricular relaxation time index (LVRTI) and left atrial emptying index (LAEI) are the earliest indicators of hypertensive heart disease due to mild essential systemic hypertension.

Adult↗
PubMed2006

Contribution of decreased atrial function in the pathogenesis of neurally mediated syncope.

One of the most important mechanisms proposed in the pathogenesis of neurally mediated syncope considers the stimulation of myocardial mechanoreceptors as the final trigger leading to reflex hypotension and bradycardia. The aim of our study was to analyze the modifications of systolic and diastolic velocities of the left ventricle by tissue Doppler echocardiography, during the upright tilt test, to confirm the presence of an increased ventricular contractility before syncope. We evaluated 47 patients (mean age 43 years) with unexplained syncope and 13 healthy subjects. Three echocardiographic recordings were collected: at baseline, during the initial 5 minutes of the test, and after 15 minutes of tilt. The upright tilt test was positive in 28 patients. During the test, all of them had a similar, significant, progressive reduction of left ventricular end-diastolic volume, left atrial area, and left atrial volume. In contrast, the left ventricular ejection fraction showed an early, more pronounced decrease in those with positive tests. By tissue Doppler echocardiography, the systolic waves remained almost unchanged, and the early filling waves decreased similarly in those with positive or negative findings and the controls. In contrast, the atrial filling waves showed a significant decrease only in patients with positive tests. In conclusion, our study did not find increased ventricular contractility before syncope. In contrast, a decreased atrial contribution to ventricular filling characterized patients with positive upright tilt test results, which, we postulate, may be an important contributory factor to vasovagal syncope.

Adult↗
PubMed1984

Mitral valve regurgitation.

The mitral apparatus is a complex structure composed of several components, each of which can be affected by a variety of diseases, resulting in mitral regurgitation. The physiologic consequences of mitral regurgitation include reduced forward stroke volume; increased left atrial volume and pressure; and reduced resistance to left ventricular ejection. The latter explains why indices of systolic left ventricular function (ejection fraction) are often increased early in the course of mitral regurgitation. With the insidious development of mitral regurgitation, the left atrium dilates to accommodate the increase in volume, thereby reducing the atrial pressure. However, with the acute development of mitral regurgitation into a nondilated left atrium, pressure rises rapidly, producing pulmonary edema. The predominant clinical symptoms in chronic mitral regurgitation of dyspnea and fatigue result from pulmonary venous hypertension and low cardiac output. The cardinal physical finding is a mitral systolic murmur. Since the murmur can assume various configurations, the most reliable way to establish its correct origin is by bedside physiologic maneuvers. Typically, in the beat following a premature contraction or after a long pause during atrial fibrillation, the murmur of mitral regurgitation is unchanged in intensity, but murmurs due to left ventricular outflow obstruction increase. Also, isometric handgrip exercise increases the intensity of the murmur and a Valsalva maneuver decreases it during the strain phase. Echocardiography is the most useful noninvasive technique for evaluating patients with mitral regurgitation. Visualization of the mitral apparatus may establish the etiology of regurgitation, and measurement of left atrial size and left ventricular size and performance is useful for assessing the functional significance of the lesion. Doppler echocardiography can establish the diagnosis of mitral regurgitation in difficult cases with multi valve disease and can estimate the severity of the regurgitation. Cardiac catheterization and angiography are usually reserved for the patient being considered for valvular surgery. The natural history of chronic mitral regurgitation is characterized by slowly progressive symptoms, and often the onset of disabling symptoms is the result of irreversible left ventricular dysfunction. Medical therapy consists of digitalis, diuretics, and vasodilators for symptomatic patients. When symptoms occur despite this therapy, valvular surgery should be considered before left ventricular function becomes abnormal.

Cardiac Catheterization↗