Catheterization diastolic pressures correlate with diastolic dyssynchrony in patients with single right ventricles.

INTRODUCTION: Diastolic dyssynchrony has correlated with pulmonary capillary wedge pressures in patients with normal cardiac anatomy. No data exist in single right ventricle (sRV) patients. Goal of this study was to determine if diastolic dyssynchrony in sRV patients correlates with ventricular end-diastolic pressures (VEDP). METHODS: Tissue Doppler imaging (TDI) and strain rate (SR) analysis of sRV patients undergoing catheterization were performed. Time interval from onset of QRS to peak TDI e'-wave was obtained. Differences in intervals were calculated: QRS (RV) - QRS (IVS) and QRS (RV) - QRS (LV). Time interval from onset of QRS to peak strain rate early diastolic wave (SRe) was obtained for the 6 segment model sRV. Standard deviation of the 6 SRe time intervals was calculated. Correlation of VEDP with timing intervals was analyzed. RESULTS: Forty sRV patients were evaluated. Age was 2.8 ± 3.5 years. Catheterization VEDP of the sRV was 9.3 ± 3.9 mmHg (median 8 mmHg range 4-24 mmHg). QRS (RV) - QRS (IVS) was 22.3 ± 18.1 msec and QRS (RV) - QRS (LV) was 23.7 ± 19.0 msec. SRe standard deviation of the sRV was 61.6 ± 23.9 msec. There was no significant correlation with VEDP and QRS (RV) - QRS (IVS) (r = 0.1, P = NS) or with QRS (RV) - QRS (LV) (r = 0.2, P = NS). There was a significant correlation of VEDP with the SRe standard deviation value (r = 0.4, P < 0.05). CONCLUSION: Diastolic dyssynchrony correlated with VEDP in patients with sRV physiology. Future studies are needed to determine the significance of these findings.

Comparing echocardiographic assessment of systolic function with catheterization data in patients with single right ventricles.

PURPOSE: Echocardiographic evaluation of systolic function in patients with single right ventricles (SRV) is important but remains challenging. Minimal data exist correlating echocardiographic indices with catheterization data in this population. The goal of this study was to evaluate which echocardiographic measurement correlated best with dP/dt (max) obtained by cardiac catheterization in SRV patients. METHODS: Patients with SRV physiology who underwent simultaneous echocardiography and cardiac catheterization were evaluated. Echocardiographic data included fractional area change % (FAC), displacement, TDI s'wave, myocardial performance index (MPI), global systolic strain, and global SR s wave. Maximum positive rate of ventricular pressure change measured as dP/dt (max) was obtained from the cardiac catheterization report. Correlations of echocardiographic and catheterization variables were examined using the Pearson correlation. RESULTS: Twenty-seven SRV patients were studied. Median age at the time of the catheterization was 11.4 months (range 0 - 132 months). dP/dt (max) values ranged from 337-1860 mmHg/s with a median of 994 mmHg/s. Mean FAC was 27.15 +/- 7.13%, displacement was 7.35 +/- 2.88 mm, TDI s' was 4.98 +/- 1.93 cm/sec, MPI was 0.41 +/- 0.17, global strain was-14.85 +/- 4.32%, and global SR s wave was -1.03 +/- 0.34 sec(-1). There were no significant correlations between dP/dt (max) and any of the echocardiographic measurements of systolic function in SRV patients. CONCLUSION: In patients with SRV physiology, catheterization-derived dP/dt (max) did not correlate with echocardiographic measurements of systolic function. Larger studies are needed to determine which non-invasive parameter best describes systolic function in patients with SRV.

Chest pain and chest wall deformity.

Chest pain and chest wall deformities are common in children. Although most children with chest pain have a benign diagnosis, some have a serious etiology for pain, so the complaint must be addressed carefully. Unfortunately, there are few prospective studies to evaluate this complaint in children. Serious causes for chest pain are rare, making it difficult to develop clear guidelines for evaluation and management. The child who appears well, has a normal physical examination, and lacks worrisome history deserves reassurance and careful follow-up rather than extensive studies. Multicenter studies are needed to better define this important symptom.

Systolic/diastolic ratio correlates with end diastolic pressures in pediatric patients with single right ventricles.

BACKGROUND: Increased ventricular end-diastolic pressure (VEDP) is a known risk factor for morbidity and mortality in patients with single right ventricle (RV) physiology. Previous studies have shown mixed results correlating echocardiographic measurements with catheter-derived VEDP in this population. Goal of this study was to evaluate if echocardiographic systolic/diastolic ratio (S/D) correlated with VEDP. METHODS: Patients with single RV physiology who underwent simultaneous echocardiography and catheterization were evaluated. Systolic and diastolic durations were measured using tricuspid inflow durations from Doppler analysis to calculate the S/D ratio. VEDP was obtained from the catheterization report. RESULTS: Twenty-seven studies were performed on patients with single RV physiology. Median age at time of catheterization was 11.4 months (range, 0-132 months). Mean VEDP was 9.9 ± 4.5 mm Hg. S/D ratio was 1.8 ± 0.5. S/D ratio significantly correlated with VEDP (r = 0.63, P < .01). Optimum value of S/D ratio for discriminating between patients with high (>10 mm Hg) vs low EDP was found to be 1.9. High S/D ratio had an area under the curve of 0.82 (0.65, 1.0), with 75% sensitivity and 89% specificity for predicting elevated VEDP. CONCLUSION: In patients with single RV physiology, S/D significantly correlated with VEDP. S/D ratio is a simple technique that may be useful in both estimating and discriminating between high and low VEDP in this complex patient population.

Outdoor air pollution: overview and historical perspective.

Outdoor air pollution is a significant public health hazard in population centers throughout the world. Recognition of air pollution as a nuisance dates back many centuries. Decades of research have established a strong link between air pollution and a spectrum of adverse health effects. Health care practitioners rarely consider the health risk of air pollution in the course of patient care and generally do not provide risk modification strategies as part of patient management. The purpose of this article is to provide front line clinicians with: 1) an overview of the evolution in scientific understanding about air pollution and its health effects, 2) an introduction to the hazards contemporary air pollution presents to patients, and 3) an introduction to the contributions of specific pollutants to outdoor air quality.

Outdoor air pollution: particulate matter health effects.

Numerous investigations studying multiple populations across a variety of environmental settings have demonstrated a strong association between ambient air particulate matter and cardiopulmonary morbidity and mortality. In most studies, the effect size of ambient air particulate pollution on health outcomes is small. However, the exposed population worldwide is very large. Accordingly, particulate air pollution appears to be an important public health hazard that makes an important contribution to the total burden of disease and death in populations across the world. Much of the evidence linking ambient air particulates with adverse health effects is derived from population-based, observational research with potential unidentified confounding exposures, precluding definitive assessments about causation and providing limited mechanistic insights. A growing body of research suggests particulate-associated adverse health effects result from the induction of proinflammatory responses in the lower respiratory tract. Ambient air particulates may increase lung cancer risk.

Outdoor air pollution: ozone health effects.

Ozone is a respiratory irritant associated with a spectrum of adverse health events. Ground-level ozone has been shown to cause decreases in lung function and has been associated with other important respiratory health effects. Some reports suggest short-term increases in ozone lead to increased cardiopulmonary mortality. Other studies have found no association between exposure and measured health effects. Outdoor air pollution consists of multiple copollutant exposures complicating definitive assessments about ambient air ozone exposure-effect relations.

Outdoor air pollution: nitrogen dioxide, sulfur dioxide, and carbon monoxide health effects.

Nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide are important ambient air pollutants. High-intensity, confined space exposure to NO2 has caused catastrophic injury to humans, including death. Ambient NO2 exposure may increase the risk of respiratory tract infections through the pollutant's interaction with the immune system. Sulfur dioxide (SO2) contributes to respiratory symptoms in both healthy patients and those with underlying pulmonary disease. Controlled human exposure studies have demonstrated that experimental SO2 exposure causes changes in airway physiology, including increased airways resistance. Both acute and chronic exposure to carbon monoxide are associated with increased risk for adverse cardiopulmonary events, including death. However, studies have not demonstrated a clear dose-dependent health risk response to increasing amounts of these pollutants except at high concentrations. In addition, a number of studies examining the effects of ambient level exposure to NO2, SO2, and CO have failed to find associations with adverse health outcomes.

Outdoor air pollution: counseling and exposure risk reduction.

Air pollution is monitored on a daily basis in large population centers in the United States and reported to the general public through a variety of media outlets as the Air Quality Index. This index is based on current national air quality standards for criteria air pollutants established by the US Environmental Protection Agency. Patients at increased risk for adverse effects of inhaled air pollutants include those who have been diagnosed with chronic lung disease and cardiovascular disease, including asthma, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, and peripheral vascular disease, although others may also be at risk during periods of unusually high pollutant levels. These patients should be educated regarding what symptoms may be related to poor air quality and how they can monitor the Air Quality Index to modify their activity to prevent symptoms and other adverse events. Heavy outdoor exertion should be avoided on days expected to have poor air quality, or performed earlier in the day on days when outdoor activity cannot be avoided. We recommend advising patients in clear, strong, personalized language that air pollution is harmful and that persons with cardiopulmonary disease are at elevated risk of experiencing a serious adverse health effect from exposure.

QRS duration and mechanical dyssynchrony correlations with right ventricular function after fontan procedure.

BACKGROUND: In studies of adult patients, increased QRS duration and mechanical dyssynchrony have been associated with decreased ventricular function. The aim of this study was to test the hypothesis that similar findings would be present in a population of patients with hypoplastic left heart syndrome (HLHS) after the Fontan procedure. METHODS: A retrospective cross-sectional study was conducted. All patients with HLHS after the Fontan procedure were eligible. QRS duration was measured using 12-lead electrocardiography. Echocardiographic measurements of mechanical dyssynchrony included Doppler tissue imaging (DTI) QRS to onset of s' wave difference between the left ventricle and the right ventricle, time to peak strain, time to peak systolic strain rate (SRs), the standard deviation of time to peak strain rate (modified Yu strain), and the standard deviation of time to peak SRs (modified Yu SRs). Right ventricular (RV) functional measurements included DTI s' wave, DTI RV myocardial performance index, global strain, global SRs, and RV fractional area change. Pearson's correlations were performed between the variables. RESULTS: Thirty-one echocardiographic studies were performed on 26 patients. The median age was 5.3 years (range, 2.5-15.4 years). QRS duration was correlated significantly with global SRs (r = 0.42). Time to peak SRs was correlated significantly with DTI s' wave (r = -0.48) and global SRs (r = 0.37). Modified Yu SRs was correlated significantly with global strain (r = 0.35) and RV fractional area change (r = -0.35). CONCLUSIONS: Both QRS duration and mechanical dyssynchrony were correlated with RV function, albeit weakly. The clinical significance of these findings is intriguing, but only larger studies will determine if these measurements are reliable in guiding treatment options for this complex patient population.

Noninvasive estimation of ventricular filling pressures in patients with single right ventricles.

BACKGROUND: Increased ventricular end-diastolic pressure (VEDP) is a known risk factor for morbidity and mortality in patients with single-ventricle physiology. Spectral Doppler tissue imaging (DTI) has been shown to modestly correlate with direct measurement of VEDP. Strain rate (SR) values, obtained via myocardial deformation, have not yet been compared with VEDP in this patient population. The goal of this study was to evaluate which of these imaging techniques correlates best with VEDP in patients with single-RV (RV) physiology. METHODS: Patients with single-RV physiology who underwent simultaneous echocardiography and catheterization were evaluated. Echocardiographic data included global longitudinal SR early diastolic wave (SRe) and SR late diastolic wave (SRa), DTI early diastolic wave (e') and DTI late diastolic wave (a') of the right ventricular free wall, and right atrioventricular valve inflow velocities (E and A waves). E/SRe and E/e' ratios were calculated. VEDP was obtained from the catheterization report. RESULTS: Twenty-seven studies were performed on patients with single-RV physiology. The median age at the time of catheterization was 11.4 months (range, 0-132 months). The mean VEDP was 9.9 ± 4.5 mm Hg. VEDP correlated significantly with E/SRe ratio (r = 0.88), global SRe (r = -0.52), SRe/SR late diastolic wave ratio (r = -0.42), and valve A velocity (r = 0.48). There were no significant correlations between VEDP and DTI measurements. Receiver operating characteristic curve analysis using an E/SRe cutoff of 150 cm showed 87.5% sensitivity and 78.9% specificity for predicting VEDP > 10 mm Hg. CONCLUSIONS: In patients with single-RV physiology, VEDP correlated strongly with SR but not with DTI measurements. SR measurements should be considered as a possible means to estimate VEDP in this complex patient population rather than DTI.