[Decreased Heart Rate Variability in Sickle Cell Anemia as Effect of Pulmonary Arterial Hypertension]

Decreased heart rate variability (HRV) is associated with increased mortality risk in various diseases. The objective of this investigation:to study HRV in patients with sickle cell anemia (SCA) and to assess the effect of pulmonary arterial hypertension (PAH) on HRV in these patients. Materials and methods. HRV registration and Doppler echocardiographic assessment of systolic pulmonary arterial pressure (PAP) was carried out in 61 stable patients with SCA and 24 healthy subjects. Results. Low frequency power (LFP) and high frequency power (HFP) were decreased in SCA patients compared to healthy subjects. Among SCA patients, PAH patients had lower  LFP and HFP than patients without PAH. In SCA patients, systolic PAP showed significant negative correlation with LFP and HFP. Conclusion. HRV is significantly decreased in SCA patients, especially in those with PAH. HRV may be particularly useful in early detection of PAH patients who may have worse prognosis and higher mortality risk.

A randomized controlled study evaluating the effects of the temperature of insufflated CO2 on core body temperature and blood gases (an experimental study)

BACKGROUND

Heated carbon dioxide (CO2) was used for pneumoperitoneum (Pp) to prevent hypothermia. This study aimed to investigate the relationship between the temperature of the insufflated CO2 and blood gases together with the core body temperature (CBT).

METHODS

A prospective controlled study was performed with 24 pigs weighing approximately 20 kg randomized into four groups of 6 pigs each. A pneumoperitoneum at 12 mmHg of pressure was applied for 60 min with the pig under general anesthesia. The CO2)temperature was 22 degrees C in group 1, 37 degrees C in group 2, and 7 degrees C in group 3. In the "sham" group, pneumoperitoneum was not applied. Arterial blood pH and partial pressure of CO2 (PaCO2) were analyzed before insufflation, every 15 min during the pneumoperitoneum, and 15 min after the desufflation. The CBT was recorded before the insufflation, every 20 min during pneumoperitoneum, and 20 min after the desufflation. Blood gas analyses and CBT records for the "sham" group were performed at the same intervals.

RESULTS

Arterial blood pH gradually decreased during pneumoperitoneum. At the 60th minute of pneumoperitoneum, a minimum decrease in arterial blood pH (0.04; p = 0.027) and a minimum increase in PaCO2 (3.67; p = 0.027) were recorded in group 3, whereas a maximum decrease in arterial blood pH (0.18; p = 0.027) and a maximum increase in PaCO2 (17.17; p = 0.027) were recorded in group 2. There was a significant negative correlation between PaCO2 and arterial blood pH in all the groups (r = -0.993; p < 0.01). The mean values of CBT decreases were statistically significant in all the groups: group 1 (p = 0.023), group 2 (p = 0.026), group 3 (p = 0.026), and "sham" group (p = 0.024).

CONCLUSIONS

The changes in PaCO2 were directly proportional and the changes in pH contrarily proportional to the temperature of the insufflated CO2. Significant differences in CBT decreases were found between the groups receiving heated gas and room temperature gas and the groups receiving heated gas and gas below room temperature.

Increased QT dispersion in sickle cell disease: effect of pulmonary hypertension

BACKGROUND

QT dispersion has been proposed to be a predictor of adverse outcomes in a variety of cardiac disease states. The objective of this study was to examine QT dispersion in patients with sickle cell disease (SCD) and to assess the effect of pulmonary hypertension (PHT) on QT dispersion.

METHODS

We performed Doppler echocardiographic assessments of pulmonary artery systolic pressure in 73 (mean age 18.5 +/- 8.0 years) steady-state SCD patients and 25 (mean age 19.6 +/- 7.2 years) healthy subjects. Resting 12-lead electrocardiogram was recorded and QT dispersion was calculated as the difference between maximum and minimum QT intervals. Bazett's formula was used to obtain a rate-corrected value of the QT interval (QTc).

RESULTS

Maximum QTc, minimum QTc and QTc dispersion were significantly increased in SCD patients compared to the control subjects (p < 0.0001, p < 0.05, p < 0.0001, respectively). Among SCD patients, patients with PHT had higher maximum QTc and QTc dispersion than patients without PHT (p < 0.0001). However, minimum QTc showed no significant differences between the two patient groups.

CONCLUSION

QTc dispersion is significantly increased in SCD patients, especially those with PHT indicating regional inhomogeneity of ventricular repolarization.

Subclinical left ventricular dysfunction in multiple sclerosis

OBJECTIVES

To investigate the left (LV) and right ventricular (RV) function in multiple sclerosis (MS) using standard echocardiography and Doppler tissue imaging (DTI).

MATERIALS AND METHODS

A total of 41 patients with definite MS and 32 healthy controls were included in the study.

RESULTS

LV end-systolic dimension was increased and LV ejection fraction was decreased in MS patients compared with controls (P < 0.05). LV end-diastolic dimension was increased in MS patients, however, did not reach significance. Among DTI parameters, mitral annular peak early diastolic velocity to peak late diastolic velocity ratio (Em/Am) was decreased in MS patients, but not reach statistical significance. No significant differences in tricuspid annular Em/Am ratio was found between MS patients and controls. A statistically significant increase of DTI derived LV myocardial performance index was found in MS patients as compared with controls. RV myocardial performance index showed a tendency to be increased in MS patients, however, did not reach significance.

CONCLUSIONS

These findings suggest subclinical LV dysfunction and preserved RV function in patients with MS.

Right ventricular and pulmonary function in sickle cell disease patients with pulmonary hypertension

The effects of sickle cell disease (SCD) on right ventricular (RV) and pulmonary function in SCD patients with pulmonary hypertension is not well-known. The aim of this study was to investigate RV and pulmonary functions in patients suffering from SCD with or without pulmonary hypertension using color tissue Doppler imaging and spirometry. We evaluated 48 asymptomatic patients with SCD. All patients underwent echocardiography with tissue Doppler imaging and pulmonary function test. Patients were divided into two groups: Group 1 consisted of 27 patients (age, 18.1 +/- 7.1 years) with normal pulmonary artery pressure, and group 2 consisted of 21 patients (age, 21.4 +/- 7.4 years) with pulmonary hypertension. Both groups were compared with a sex- and age-matched control group including 24 normal healthy subjects (age, 19.8 +/- 9.2 years). Tricuspid lateral annular systolic (S (m)) and early diastolic velocity (E (m)) were higher in group 1 than group 2 and the control group (p < 0.05). Tricuspid lateral annular late diastolic velocities (A (m)), isovolumetric contraction time, and myocardial performance index (MPI) were higher and the E (m)/A (m) ratio was lower in group 2 than group 1 and the control group (p < 0.05). However, no differences were found in the tricuspid lateral annular E (m) deceleration time, ejection time, and isovolumetric relaxation time between group 1, group 2, and the control group. Tricuspid lateral annular S (m) and E (m) were similar in group 2 and the control group. Forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and the diffusion capacity of the lung for carbon monoxide were decreased in both groups of patients compared to the control group (p < 0.05). However, there was no difference in respiratory rate, FEV(1)/FVC ratio, peak expiratory flow, and total lung capacity between group 1, group 2, and the control group. There were no differences in any indices of lung function between the two groups of patients. MPI is useful index to evaluate RV function in patients with SCD. RV diastolic function was disturbed in only SCD patients with pulmonary hypertension. On the other hand, the restrictive pattern of pulmonary function abnormalities had developed in both groups of patients.

Right ventricular diastolic abnormalities in rheumatoid arthritis and its relationship with left ventricular and pulmonary involvement. A tissue Doppler echocardiographic study

OBJECTIVES

To investigate right ventricular diastolic function in rheumatoid arthritis (RA) and its relationship with left ventricular and pulmonary involvement.

METHODS

Thirty-five RA patients and 30 healthy subjects were submitted to conventional Doppler (CE) and tissue Doppler echocardiography (TDE) to assess left and right systolic and diastolic function and to estimate maximal arterial systolic pulmonary pressure (PAP). To detect pulmonary involvement, pulmonary function tests and high-resolution computed tomography (HRCT) scans were performed in all RA patients.

RESULTS

An abnormal RV filling, as expressed byan inverted tricuspid (Tr.) E/A ratio, was detected in 12 (34%) of the 35 RA patients and in 2 (7%) of the 30 controls (P<0.004). If compared to CE findings, prevalence of RV diastolic abnormalities were found higher in patients with RA by TDE (RV annulus Em/Am ratio <1 (in 31 (89%) of 35 patients) (P = 0.002). Twenty-two (63%) of 35 patients had abnormal HRCT findings. Pulmonary involvement with pulmonary hypertension (PHT) (36+/-5 mmHg) was detected in 10 (29%) of 35 RA. In this group, increase of RV annulus and basal Am wave, decrease of Tr. E/A ratio and RV annulus Em/Am ratio were statistically significant compared to RA (12 (34%) of 35) patients with pulmonary involvement who had normal PAP (19+/-5 mmHg), (P = 0.014, P = 0.006, P = 0.015, P = 0.049, respectively).

CONCLUSIONS

This study points out an impaired RV filling in a significant part of RA patients without overt heart failure. Impairment of RV diastolic function may be a predictor of subclinic myocardial and pulmonary involvement in patients with RA.