Superior vena cava flow and tricuspid anular motion after cardioversion of atrial fibrillation, and role of right atrial relaxation on systolic venous return

Treatment of right ventricular dysfunction and heart failure in pulmonary arterial hypertension

Right heart dysfunction and failure is the principal determinant of adverse outcomes in patients with pulmonary arterial hypertension (PAH). In addition to right ventricular (RV) dysfunction, systemic congestion, increased afterload and impaired myocardial contractility play an important role in the pathophysiology of RV failure. The behavior of the RV in response to the hemodynamic overload is primarily modulated by the ventricular interaction and its coupling to the pulmonary circulation. The presentation can be acute with hemodynamic instability and shock or chronic producing symptoms of systemic venous congestion and low cardiac output. The prognostic factors associated with poor outcomes in hospitalized patients include systemic hypotension, hyponatremia, severe tricuspid insufficiency, inotropic support use and the presence of pericardial effusion. Effective therapeutic management strategies involve identification and effective treatment of the triggering factors, improving cardiopulmonary hemodynamics by optimization of volume to improve diastolic ventricular interactions, improving contractility by use of inotropes, and reducing afterload by use of drugs targeting pulmonary circulation. The medical therapies approved for PAH act primarily on the pulmonary vasculature with secondary effects on the right ventricle. Mechanical circulatory support as a bridge to transplantation has also gained traction in medically refractory cases. The current review was undertaken to summarize recent insights into the evaluation and treatment of RV dysfunction and failure attributable to PAH.

Assessing the effect of preoperative levosimendan on renal function in patients with right ventricular dysfunction

The Acute Kidney Injury Network (AKIN) classification considers SCr values, urea and urine output in order to improve timely diagnose ARF and improve patient prognosis by early treatment. Preoperative levosimendan is a new way for cardiac and kidney protection, we try to evaluate this drug in fifteen patients comparing values of AKIN scale parameters pre and post cardiac surgery in patients with right ventricle dysfunction.

Respiratory variation in superior vena cava flow in patients with chronic obstructive pulmonary disease: estimation of pulmonary hypertension using Doppler flow index

Patients with chronic obstructive pulmonary disease (COPD) are difficult to assess by conventional transthoracic echocardiography (TTE) because of emphysematous lungs or mediastinal deviation. We hypothesized that superior vena cava (SVC) flow is related to pulmonary circulation and may be useful for the detection of pulmonary hypertension (PH) in patients with COPD that cannot been assessed by direct evaluation using the tricuspid regurgitant Doppler velocity. SVC Doppler flow velocities were examined in 46 patients with COPD and the pressure gradient between the right ventricular and right atrial pressure (RV-RADeltaP) was calculated by tricuspid regurgitant Doppler velocities. The patients were divided into 2 groups: 11 patients with PH (RV-RADeltaP > 25 mm Hg) were compared with 35 without PH. There was no significant difference in the maximal SVC peak systolic forward flow velocity during inspiration (INS) between these 2 groups. However, the minimal SVC peak systolic forward flow velocity during expiration (EXP) in the group with PH was significantly higher than that in the group without PH (37.4 +/- 20.0 cm/s vs 26.4 +/- 8.5 cm/s, P =.01). Linear regression analysis revealed a significant correlation between RV-RADeltaP and the EXP/INS ratio (r = 0.61, P <.001). In COPD patients with PH, the increased expiratory SVC systolic flow supplemented the preload for the impaired right ventricular filling flow caused by PH, thereby maintaining the transtricuspid driving pressure. Our observation suggests that respiratory variation in SVC systolic forward flow may be a sensitive Doppler flow index for evaluating severity of PH in patients with COPD that cannot been assessed by conventional TTE.

Assessment of left ventricular filling pressures by Doppler in the presence of atrial fibrillation

BACKGROUND

Although Doppler echocardiography can be used to estimate left ventricular filling pressures (LVFPs) in patients in sinus rhythm, its utility in atrial fibrillation is unknown.

METHODS AND RESULTS

An initial training population of 30 patients (17 men, 13 women: mean age, 69 +/- 9 years; range, 48 to 87 years) was studied. Measurements of LVFP were obtained simultaneously with pulsed Doppler recordings of mitral and pulmonary venous flow velocities and color M-mode recording of the flow propagation velocity of the mitral inflow. Measurements were averaged over 10 cardiac cycles. In addition, left atrial volume was derived from the apical four-chamber view. Significant relations were observed between LVFP and several parameters derived from the transmitral and pulmonary venous velocity and left atrial volume. The best relations were observed with the peak acceleration (PkAcc) of the mitral velocity (r = .84), isovolumic relaxation time (IVRT) (r = .76), mean early (E) velocity (r = .6), and the ratio of peak E velocity to color M-mode flow propagation velocity (r = .65). The best model obtained by multilinear regression analysis (r = .88) included PkAcc and IVRT. The equation LVFP = 22+0.005 (PkAcc)-0.183(IVRT) was tested in 30 additional patients (12 women and 18 men: mean age, 65 +/- 10.6 years; range, 43 to 87 years) with similar results (r = .87). When all 60 patients were combined, the mean +/- ISD difference between predicted and observed pressure was -0.88 +/- 3.6 mm Hg.

CONCLUSIONS

LVFPs can be estimated with Doppler echocardiography in patients with atrial fibrillation.

A practical guide to assessment of ventricular diastolic function using Doppler echocardiography

Doppler assessment of diastolic function has become a standard part of routine echocardiographic examination and imparts information relevant to a patient's functional class, management and prognosis. This review describes the Doppler patterns of diastolic function relative to physical signs and physiology. A continuum of doppler patterns of diastolic function exists, including normal diastolic function, impaired relaxation, pseudonormal filling, restriction, constriction and tamponade. These patterns evolve from one to another in a single individual, with changes in disease evolution, treatment and loading conditions. New applications of continuous wave Doppler, color Doppler M-mode and Doppler tissue imaging are refining our understanding of diastolic function.

Atrial reservoir and active transport function after cardioversion of chronic atrial fibrillation

Atrial reservoir function has not been studied after successful cardioversion of chronic atrial fibrillation. Using transthoracic and transesophageal Doppler echocardiography, we measured flow velocity-time integrals of the systolic forward (Sa), diastolic forward (Da), and diastolic reversed (rAa) waves of flow velocity waveforms in the pulmonary vein and the superior vena cava, and those of the early diastolic (Ea) and late diastolic (Aa) waves of the transmitral and transtricuspid flow velocity waveforms. The left and right atrial storage fractions (LASF, RASF), indexes of atrial reservoir function, were determined as the ratios of the atrial storage volume to the ventricular stroke volume; (Sa - rAa)/(Sa - rAa + Da). The left and right atrial active contraction fractions (LAACF, RAACF), indexes of atrial active transport function, were also determined as the ratios of the atrial active contraction volume to the left ventricular stroke volume; Aa/(Ea + Aa). These indices were evaluated periodically in 12 patients with non-valvular chronic atrial fibrillation before and 1-4 days after direct current cardioversion of atrial fibrillation; in 8 of the patients, the indices were also evaluated 1-3 months after the cardioversion. An additional 10 patients in sinus rhythm served as controls. Both the LASF and RASF were low during atrial fibrillation; the values increased significantly 14 days after successful cardioversion (P < 0.01 P < 0.01), and continued to increase at 1-3 months. The LASF and RASF values 1-3 months after cardioversion were comparable to those in control subjects. Both the LAACF and RAACF also increased significantly from 1-4 days to 1-3 months after cardioversion (P < 0.05, P < 0.01), becoming comparable to those in control subjects. During the 3 months after successful cardioversion of non-valvular chronic atrial fibrillation, left and right atrial reservoir function and left and right atrial active transport function increased progressively, becoming comparable to values in the control subjects.

Atrial and ventricular function after cardioversion of atrial fibrillation

OBJECTIVE

Previous studies on atrial recovery after cardioversion of atrial fibrillation have not taken into account new knowledge about the pathophysiology of transmitral and transtricuspid flow velocity patterns. It is possible to shed further light on this problem if atrioventricular inflow velocity, venous filling pattern, and atrioventricular annulus motion are recorded and interpreted together.

DESIGN

Prospective examinations of mitral and tricuspid transvalvar flow velocities, superior caval and pulmonary venous filling, and mitral and tricuspid annulus motion were recorded using Doppler echocardiography. Examinations were performed before and 24 hours, 1 month, and 20 months after cardioversion.

SETTING

Tertiary referral centre for cardiac disease with facilities for invasive and non-invasive investigation.

PATIENTS

16 patients undergoing cardioversion of atrial fibrillation in whom sinus rhythm had persisted for 24 hours or more.

RESULTS

Before conversion there was no identifiable A wave in transvalvar flow recordings. The total motion of the tricuspid and mitral annulus was subnormal and there was no identifiable atrial component. Venous flow patterns in general showed a low systolic velocity. After conversion, A waves and atrial components were seen in all patients and increased significantly (P < 0.01) with time. There was a similar time course for the amplitude of annulus atrial components, an increased systolic component of venous inflow, an increased A wave velocity, and a decreased E/A ratio of the transvalvar velocity curves. The ventricular component of annulus motion was unchanged. Changes in general occurred earlier on the right side than the left.

CONCLUSIONS

This study indicates that, in addition to the previously known electromechanical dissociation of atrial recovery that exists after cardioversion of atrial fibrillation, there may also be a transient deterioration of ventricular function modulating the transvalvar inflow velocity recordings. Function on the right side generally becomes normal earlier than on the left. Integration of information from transvalvar inflow curves, annulus motion, and venous filling patterns gives additional insight into cardiac function.

Time-course of recovery of atrial contraction after cardioversion of chronic atrial fibrillation

We aimed to study the time-course of recovery of atrial contraction after cardioversion of chronic atrial fibrillation (duration of more than 3 months) to sinus rhythm. Using M-mode, two-dimensional and pulsed Doppler echocardiography, we determined left atrial (LA) and ventricular (LV) dimensions, peak velocities, and velocity-time integrals of early and atrial filling velocity-time profiles in both LV and right ventricular (RV) inflows (peak E and peak A, Ea and Aa). Results of the LA and LV functions in seven elderly patients (an initial study group) were as follows. The extent of the LA dimensional reduction resulting from atrial contraction was significantly increased up to 5-8 weeks compared with values 0-1 day after cardioversion [from 1.3 +/- 0.8 (mean +/- SD) mm to 3.9 +/- 1.1, P < 0.01]. In conjunction with the progressive increase in peak A, the ratio of peak E to peak A (peak E/A) was significantly decreased and reached a plateau at 5-8 weeks (from 1.93 +/- 0.59 to 0.67 +/- 0.11, P < 0.01). LV fractional shortening was increased significantly 5-8 weeks after cardioversion (from 0.20 +/- 0.06 to 0.29 +/- 0.05, P < 0.01). Since a large part of the improvement in LA contraction was expected to occur in an early stage after cardioversion, we studied eight additional patients more frequently in the early stage (an additional study group). Furthermore, we studied the time course of LA and right atrial (RA) contractions.(ABSTRACT TRUNCATED AT 250 WORDS)