Left Ventricular Right Ventricular Research Articles

Right/left ventricular area ratio does not correlate with right ventricular impedance

The right ventricular/left ventricular (RV/LV) area ratio is often used to titrate airway pressure during mechanical ventilation [1]. This ratio has only been validated for detecting pulmonary embolism [2]. The purpose of this study was to evaluate the relationship between RV/LV area ratio and RV impedance in a pig model with a closed pericardium.

Assessment of correlation between CT angiographic clot load score, pulmonary perfusion defect score and global right ventricular function with dual-source CT for acute pulmonary embolism

The purpose of this study was to prospectively investigate the correlation between CT angiographic clot load (CTACL) score, pulmonary perfusion defect (PPD) score and the global right ventricular function in the assessment of pulmonary embolism (PE) severity. 49 patients with acute PE, who underwent dual-source CT scan, were included in the study. CT angiography and perfusion imaging were performed. Data from electrocardiogram-gated coronary angiography scanning protocol were used for right ventricular function analysis. Two readers evaluated the CTACL and PPD scores using the Qanadli and Chae methods, respectively. The PPD score had a strong positive correlation with the CTACL score (r=0.72, p<0.001) and both scores in turn had a strong positive correlation with the right ventricular/left ventricular (RV/LV) diameter ratio (r=0.60, r=0.62, p<0.001). However, the PPD score had a strong negative correlation with ejection fraction (EF) (r=-0.63, p<0.001) while the CTACL score had a low negative correlation with EF (r=-0.33, p=0.02). Between the RV/LV<1 group (n=35) and the RV/LV >1 group (n=14), the PPD score, CTACL score, pulmonary artery trunk diameter, EF and reflux of inferior vena cava were significantly different, all with p<0.001. The end-systolic volume (p=0.01) was significantly different but the end-diastolic volume (p=0.11) and stroke volume (p=0.08) showed no statistically significant difference between the two groups. Therefore, considering PPD scores, CTACL scores and cardiovascular manifestations together may be helpful in the evaluation of PE severity.

Correlation of CT angiographic pulmonary artery obstruction scores with right ventricular dysfunction and clinical outcome in patients with acute pulmonary embolism

ObjectiveTo correlate CTA pulmonary artery obstruction scores (OS) with right ventricular dysfunction (RVD) and clinical outcome in patients with acute pulmonary embolism (PE). Materials and methodsIn a prospective study of 50 patients (66±12.9 years) with PE pulmonary artery OS (Qanadli, Mastora, and Mastora central) were assessed by two radiologists. To assess RVD all patients underwent echocardiography within 24h. Furthermore, RVD on CT was assessed by calculating the right ventricular/left ventricular (RV/LV) diameter ratios on transverse (RV/LVtrans) and four-chamber views (RV/LV4ch) as well as the RV/LV volume ratio (RV/LVvol). OS were correlated with RVD and the occurrence of adverse clinical outcomes (defined as death, need for intensive care treatment, or cardiac insufficiency ≥NYHA III). ResultsMean Mastora, Qanadli, and Mastora central OS were 26.4±17.7, 12.6±9.9 and 7.5±9, respectively. Echocardiography demonstrated moderate and severe RVD in 10 and 5 patients, respectively. Patients with moderate and severe RVD showed significantly higher Mastora central scores than patients without RVD (14±10.8 vs. 5.9±7.8 [p=0.05]; 17.6±13.2 vs. 5.9±7.8 [p=0.038]). A relevant correlation (i.e. r≥0.6) between OS and CT parameters for RVD were only found for the Mastora score and the Mastora central score (RV/LV4ch: r=0.61 and 0.68, RV/LVvol: r=0.61 and 0.6). 18 patients experienced an adverse clinical outcome. None of the OS differed significantly between patients with and without adverse clinical outcome. ConclusionPulmonary artery obstruction scores can differentiate between patients with and without RVD. However, in this study, obstruction scores were not correlated to adverse clinical outcome.

Relation of subclinical left and right ventricular dysfunctions measured by computed tomography angiography with the severity of coronary artery disease

Ventricular dysfunction in asymptomatic patients is directly linked to the eventual development of symptomatic congestive heart failure. This study investigates whether subclinical left ventricular (LV) and right ventricular (RV) dysfunctions measured by computed tomography angiography is associated with the severity of coronary artery disease (CAD). We studied 1608 consecutive patients with suspected CAD (age 62 ± 10 years, 64% male), who underwent coronary artery calcium (CAC) scanning and computed tomography angiography. RV and LV volumes at end systole and end diastole were measured, and stroke volume and ejection fraction were calculated using the Simpson method and piecewise smooth subdivision surface (PSSS) method. Analysis by Simpson was performed on short axis and apical four-chamber views. Axial images were used to measure RV and LV volumes by the PSSS method. CAD was defined as normal, nonobstructive, and obstructive (0% stenosis, luminal stenosis 1-49 and 50%+, respectively). There was a strong agreement between PSSS and Simpson method RV ejection fraction (RVEF) and LV ejection fraction (LVEF) measurement. RVEF and LVEF decreased proportionally from CAC 0 to CAC 100+, also from normal-to-diseased coronaries (P=0.001). After adjustment for cardiovascular risk factors, the mean LVEF and RVEF decreased 2.8 and 2.4%, respectively in CAC 100+ compared with CAC 0. Similarly, LVEF and RVEF decreased significantly in nonobstructive CAD (-3.5 and -3.1%, respectively) and obstructive CAD (-5.9 and -4.5%, respectively) compared with normal coronaries, respectively (P<0.05). The relative risk of each 5% decrease in LVEF and RVEF was 1.33 and 1.29 for nonobstructive CAD and 1.54 and 1.33 for obstructive CAD, respectively. The presence and severity of coronary atherosclerosis is significantly associated with subclinical RV and LV dysfunctions.

Abnormalities in Cardiac Structure and Function in Adults with Sickle Cell Disease are not Associated with Pulmonary Hypertension

In sickle cell disease (SCD), pulmonary hypertension (assessed by tricuspid regurgitant jet [TRJ] velocity ≥ 2.5 m/sec) is associated with increased mortality. The relationships among TRJ velocity and left ventricular (LV) and right ventricular (RV) systolic and diastolic function (i.e., relaxation and compliance) have not been well characterized in SCD. A prospective study was conducted in 53 ambulatory adults with SCD (mean age, 34 years; range, 21-65 years) and 33 African American controls to define the relationship between LV and RV function and TRJ velocity using echocardiography. Subjects with SCD had larger left and right atrial volumes and increased LV mass compared with controls. When patients with SCD were compared with controls, LV and RV relaxation (i.e., E') were similar. Among subjects with SCD, pulmonary hypertension (TRJ ≥ 2.5 m/sec) was present in 40%. Higher TRJ velocity was correlated with larger left atrial volumes in patients with SCD. Additionally, some measures of LV (peak A, lateral and septal annular E/E' ratio) and RV (tricuspid valve E/E' ratio) compliance were correlated with TRJ velocity. No other measures of LV and RV systolic function or LV diastolic function (i.e., relaxation and compliance) were associated with TRJ velocity. Ambulatory adults with SCD exhibited structural (i.e., LV and RV chamber enlargement) and functional (i.e., higher surrogate measures of LV and RV filling pressure) abnormalities compared with the control group. In subjects with SCD, few abnormalities of LV and RV structure and function were associated with TRJ velocity.

Right ventricular function predicts cardiovascular events in outpatients with stable cardiovascular diseases: preliminary results

Right ventricular (RV) function impacts the outcome in cardiac and pulmonary diseases such as heart failure, pulmonary hypertension, myocardial infarction, valvular, and congenital heart diseases. To our knowledge, simultaneous evaluation of left ventricular (LV) and RV systolic and diastolic echocardiographic indices in outpatients with clinically stable cardiovascular diseases has never been performed. Thus, we designed a prospective cohort study to define the prognostic power of these parameters. One hundred and sixty-three patients were submitted to transthoracic echocardiography with multiparametric and tissue Doppler evaluation of the following indices: ejection fraction, MAPSE, TAPSE, RV presystolic peak, LV and RV diastolic function, pulmonary artery systolic pressure, and functional mitral regurgitation. All these parameters and clinical variables (age, sex, and prior cardiovascular events) were entered in a multivariable Cox regression model. The primary end point was the occurrence of major cardiovascular events (MACEs) during the follow-up period. Twenty-one MACEs were observed; in the final multivariable Cox regression model only prior cardiovascular events (B 1.305, p 0.004, 95% CI 1.523-8.933), age (B 0.067, p 0.005, 95% CI 1.020-1.121), and TAPSE (B -1.065, p 0.026, 95% CI 0.135-0.883) were associated with MACEs. TAPSE, a simple and reproducible echocardiographic index, may be viewed as an early echocardiographic marker of heart involvement in atherosclerosis. We believe that TAPSE may be useful in clinical practice for risk stratification.

Ventricular Tachycardia Originating from Apical Septum in a Case with Dilated Cardiomyopathy: Correlation of Electroanatomical Data with Post-Mortem Histology

Introduction: We report a 41-year-old male of pleomorphic ventricular tachycardia (VT) complicated with dilated cardiomyopathy, treated with RF ablation, followed by autopsy of the heart. Case Presentation: 12-lead ECG during one of VTs exhibited rS pattern in leads V1 to V6, consistent with septoapical origin. Bipolar endocardial voltage map revealed small zone of low voltage in the left ventricular (LV) apex. Good pacemap was obtained from the right ventricular (RV) apex, but was not obtained from the LV apex. Activation map revealed the earliest activation site in both RV and LV apex. No diastolic potentials during the ongoing VT were detected. The VT was terminated by several RF deliveries at LV apex, but remained inducible. On autopsy of the heart, scattered fibrosis was observed in midmyocardium of LV, and was more prominent in septum than in LV free wall. The lesions produced by RF delivery were non-transmural in RV septum (a depth of 6 mm) and LV free wall (2.5 mm). Conclusion: The VT originated from apical, intraseptal injured myocardium with a breakthough to the RV, which could not effectively ablate from either apex.

Torsional Mechanics of the Left Ventricle in Patients After Surgical Repair of Tetralogy of Fallot

This study aimed to test the hypothesis that alteration of left ventricular (LV) torsional mechanics occurs in patients after repair of tetralogy of Fallot (TOF) and is associated with right ventricular (RV) volume overload and changes in LV configuration. Fifty-five TOF patients aged 19.0 ± 8.1 years and 27 age-matched healthy controls were studied. The LV and RV volumes were measured using 3-dimensional echocardiography while LV geometry was quantified by the diastolic eccentricity index (EI). The LV peak systolic torsion and systolic twisting and diastolic untwisting velocities were determined by speckle tracking. Compared with controls, patients had significantly greater RV end-systolic (P < 0.001) and diastolic (P < 0.001) volumes and LV diastolic EI (P < 0.001). In contrast, LV peak apical rotation (P < 0.001), systolic torsion (P = 0.004), systolic twisting velocity (P = 0.001), and diastolic untwisting velocity (P = 0.001) were lower in patients than in controls. For the whole cohort, RV EDV and LV diastolic EI correlated negatively with peak systolic torsion, systolic twisting velocity, and diastolic untwisting velocity (all P ≤ 0.001). Systolic torsion correlated strongly with diastolic untwisting velocity (r = 0.72, P < 0.001), while systolic twisting velocity correlated with LV ejection fraction (r = 0.3, P = 0.005). LV torsional mechanics is impaired and is negatively related to RV volume overload and LV eccentricity in patients after TOF repair.

Role of intraoperative electrical parameters in predicting reverse remodelling after cardiac resynchronization therapy and correlation with interventricular mechanical dyssynchrony

Cardiac resynchronization therapy (CRT) was shown to reverse left ventricular (LV) remodelling in heart failure (HF) patients. We aimed to investigate whether intraoperative electrical parameters (IEP) were predictive factors of LV reverse remodelling and were correlated with mechanical dyssynchrony indexes. Eighty-six patients with HF underwent CRT. At implant, several electrical and echocardiographic parameters were evaluated and, at 6 months, responders were defined by a relative increase in LV ejection fraction ≥25% compared with baseline. Several IEPs were shown to predict LV reverse remodelling. Receiver operating curve analysis revealed the ratio between QRS duration during biventricular pacing (BVp) and right ventricular pacing (RVp) [QRS(BVp)/QRS(RVp)] as the best predictor of LV functional recovery after CRT (AUC = 0.72; 95% confidence limit 0.57-0.82; P < 0.001). Responders showed a lower value of QRS(BVp)/QRS(RVp) when compared with non-responders (0.74 ± 0.05 vs. 0.8 ± 0.1; P < 0.005) and 0.78 was the value associated with the best predictive accuracy. The interval between the onset of RV lead and LV lead electrograms (RVegm-LVegm) during baseline rhythm correlated directly with the interventricular mechanical delay (IVMD) (r = 0.68; P < 0.0001) and with its reduction (delta IVMD) at follow-up (r = 0.66; P < 0.0005). Intraoperative electrical parameters can predict LV functional recovery after CRT and they are correlated with interventricular mechanical resynchronization at follow-up.

Effects of High Intensity Exercise on Biventricular Function Assessed by Cardiac Magnetic Resonance Imaging in Endurance Trained and Normally Active Individuals

Although several investigations have demonstrated that prolonged aerobic exercise results in decreased left ventricular (LV) function, few have examined the impact of an acute bout of high-intensity exercise on right ventricular (RV) and LV systolic and diastolic function. Cardiac magnetic resonance imaging with tagging was used to study the impact of high-intensity interval exercise on biventricular function in 9 endurance-trained (ET; Vo(2)max 69 +/- 7 ml/kg/min) and 9 normally active (NA; Vo(2)max 44 +/- 9 ml/kg/min) men. Subjects underwent baseline cardiac magnetic resonance imaging assessments (pre) and then performed an average of 14 1-minute intervals at 97 +/- 11% (NA) and 99 +/- 6% (ET) of peak power output, separated by 2 minutes of recovery at 21 +/- 6% (NA) and 21 +/- 9% (ET) of peak power output. After exercise, 2 cardiac magnetic resonance imaging assessments (post 1 at 6.2 +/- 2.6 minutes and post 2 at 38.4 +/- 3.8 minutes) were completed. RV and LV ejection fractions, twist, basal and apical rotation rates, rate of untwisting, circumferential strain, and timings were examined. No significant change in RV and LV ejection fractions, twist, untwisting rate, or strain after exercise occurred in the NA group. In the ET group, RV ejection fraction (pre 56 +/- 4%, post 1 54 +/- 4%, post 2 54 +/- 3%) and LV ejection fraction (pre 62 +/- 4%, post 1 59 +/- 4%, post 2 58 +/- 4%) were decreased at post 1 and post 2, while untwisting rate, apical rotation rate, and circumferential strain were decreased at post 2 (all p values <0.05). In conclusion, biventricular systolic and diastolic dysfunction occurred after 14 minutes of high-intensity exercise in ET athletes, a phenomenon not observed in NA subjects.

Right ventricular myocardial involvement in either physiological or pathological left ventricular hypertrophy: an ultrasound speckle-tracking two-dimensional strain analysis

To analyse right ventricular (RV) myocardial deformation in patients with left ventricular (LV) hypertrophy secondary to either hypertrophic cardiomyopathy (HCM) or athlete's competitive endurance training. Standard Doppler echo, exercise stress echo, and 2D speckle-tracking strain echocardiography (2DSE) of RV longitudinal deformation in RV septal and lateral walls were performed in 50 top-level endurance athletes and in 35 patients with HCM, all men, having evidence of LV hypertrophy. Right ventricular global longitudinal strain (GLS) was calculated by averaging local strains along the entire right ventricle. The two groups were comparable for age and blood pressure, whereas athletes showed lower heart rate and increased body surface area than HCM. Interventricular septal thickness was higher in HCM, whereas both LV and RV end-diastolic diameters (LVEDD and RVEDD) and LV stroke volume were increased in athletes. Right ventricular tricuspid annulus systolic excursion was comparable between the two groups. Conversely, RV GLS and regional peaks of RV myocardial strain were significantly impaired in patients with HCM (all P < 0.001). Multiple linear regression models detected an independent association between RV GLS and LVEDD (beta-coefficient = -0.68, P < 0.0001) in athletes, as well as an independent correlation of the same RV GLS with septal thickness (beta = 0.63, P < 0.0001) in HCM. An RV GLS cut-off value of -0.16% differentiated athletes and HCM with an 86% sensitivity and a 92% specificity. Furthermore, in the overall population, RV GLS (beta = 0.51, P < 0.0001) was a powerful independent predictor of maximal workload during exercise stress echo. Right ventricular myocardial systolic deformation is positively influenced by preload increase in athletes and negatively associated with increased septal thickness in HCM. Therefore, 2DSE may represent a useful tool in the differential diagnosis between athlete's heart and HCM, underlining the different involvement of RV myocardial function in either physiological or pathological LV hypertrophy.

Cardiac Function Assessed by Transesophageal Echocardiography During Pectus Excavatum Repair

We assessed end-diastolic right ventricular (RV) dimensions and left ventricular (LV) ejection fraction by use of intraoperative transesophageal echocardiography before and after surgical correction of pectus excavatum in adults. A prospective study was conducted including 17 patients undergoing surgical correction of pectus excavatum according to the technique of Ravitch-Shamberger between 1999 and 2004. Intraoperative transesophageal echocardiography was performed under general anesthesia before and after surgery to assess end-diastolic RV dimensions and LV ejection fraction. The end-diastolic RV diameter and area were measured in four-chamber and RV inflow-outflow view, and the RV volume was calculated from these data. The LV was assessed by transgastric short-axis view, and its ejection fraction was calculated by use of the Teichholz formula. The end-diastolic RV diameter, area, and volume all significantly increased after surgery (mean values +/- SD, respectively: 2.4 +/- 0.8 cm versus 3.0 +/- 0.9 cm, p < 0.001; 12.5 +/- 5.2 cm(2) versus 18.4 +/- 7.5 cm(2), p < 0.001; and 21.7 +/- 11.7 mL versus 40.8 +/- 23 mL, p < 0.001). The LV ejection fraction also significantly increased after surgery (58.4% +/- 15% versus 66.2% +/- 6%, p < 0.001). Surgical correction of pectus excavatum according to Ravitch-Shamberger technique results in a significant increase in end-diastolic RV dimensions and a significantly increased LV ejection fraction.

Quantifying the Role of Regional Dyssynchrony on Global Left Ventricular Performance

We hypothesize that left ventricular (LV) segmental dyssynchrony, quantified by paradoxical systolic wall thinning, determines changes in global LV performance in a model of canine right ventricular (RV) pacing-induced dyssynchrony and the response to cardiac resynchronization therapy (CRT). Quantification of LV dyssynchrony is important to assess the impact of CRT. Seven pentobarbital-anesthetized open-chest dogs had LV pressure-volume relations and mid-LV short-axis echocardiographic speckle tracking radial strain imaging during right atrial (RA) pacing, RV pacing to simulate left bundle branch block, and CRT using RV pacing plus either LV free-wall (CRTfw) and apical (CRTa) pacing. The area under the segmental LV time-radial strain positive and negative curves defined global thickening and thinning, respectively. Dyssynchrony was defined as the maximum time difference between earliest and latest peak segmental positive strain among 6 radial sites. RA pacing had minimal dyssynchrony (58 + or - 40 ms). RV pacing induced both dyssynchrony (213 + or - 67 ms, p < 0.05) and reduced LV stroke work (SW) (67 + or - 51 mJ, p < 0.05). CRTfw and CRTa decreased dyssynchrony (116 + or - 47 ms and 50 + or - 34 ms, respectively, p < 0.05 vs. RV pacing), but only CRTa restored LV SW to RA pacing levels. RV pacing decreased global thickening (129 + or - 87%.ms) compared with RA pacing (258 + or - 133%.ms, p < 0.05), whereas CRTfw and CRTa restored regional thickening to RA pacing levels (194 + or - 83%.ms and 230 + or - 76%.ms, respectively). The sum of thickening and thinning during RV (230 + or - 88%.ms vs. 258 + or - 133%.ms, p < 0.05) correlated (r = 0.98) with RA thickening, suggesting that all the loss of LV function was due to thinning. Dyssynchrony causes proportional changes in regional LV wall thinning and global LV SW that were reversed by CRT, suggesting that dyssynchrony impairs LV systolic function by causing paradoxical regional wall thinning and that CRT effectiveness can be monitored by its reversal. Thus, monitoring paradoxical regional thinning reversal may be used to define CRT effectiveness.

Value of right ventricular-left ventricular interlead electrical delay to predict reverse remodelling in cardiac resynchronization therapy: the INTER-V pilot study

Few studies have systematically evaluated the value of intra-procedural parameters in predicting response to cardiac resynchronization therapy (CRT). We investigated whether intracardiac (electrogram) measurements of electrical delays between the positioned right ventricular (RV) and left ventricular (LV) leads at implantation could predict the mid-term CRT response. Fifty-two patients underwent CRT implantation according to standard techniques and clinical indications. The RV-LV interlead electrical delay measured during spontaneous rhythm and the difference between the pacing-induced (Deltap) RV-LV interlead electrical delays measured during RV and LV pacing were defined intraoperatively using the electrical depolarizations registered at the ventricular leads on the device programmer. At 6 months, a reduction of LV end-systolic volume > or = 15% was used to define CRT responders. Responders (62%), when compared with non-responders, showed a higher proportion of ischaemic aetiology (P = 0.007) and a lower value of DeltapRV-LV interlead electrical delay (22.1 +/- 18.4 vs. 46.3 +/- 15.0 ms, P = 0.0001). At multivariate analysis, the DeltapRV-LV interlead electrical delay was the only independent predictor of response to CRT (P = 0.001). For such a parameter, the receiving operating characteristic curve analysis identified a cut-off value of 42 ms corresponding with the highest accuracy: sensitivity 90.6%; specificity 70%; positive and negative predictive value 83% and 82%, respectively. Conversely, no difference was ascertained between responders and non-responders when RV-LV interlead electrical delay was measured during spontaneous rhythm (76.1 +/- 28.5 vs. 89.6 +/- 21.2, P = 0.078). Intraprocedural measuring of paced RV-LV interlead electrical delay obtained during RV and LV pacing predicts mid-term CRT response.

Hemodynamic and histomorphometric characteristics of heart failure induced by aortic stenosis in the guinea pig: comparison of two constriction sizes

Heart failure induced by aortic stenosis in young guinea pigs could constitute an interesting model for pharmacology, but its natural history needs to be characterized. One hundred five guinea pigs (3-4 weeks old) underwent thoracic aortic banding with 12- (B12G) or 14-gauge (B14G) needles or similar sham operations (S12G, S14G). Animals alive at 7 d (S12G, n = 16; B12G, n = 28; S14G, n = 19; B14G, n = 27) were assessed at 60 or 120 d. At 60 d, compared with sham groups, left ventricular (LV) mass and wall thickness increased in operated groups, but LV systolic pressure and right ventricular (RV) wall thickness only increased in the B14G group. At 120 d, B12G animals still showed signs of compensated hypertrophy with LV and RV wall thickening (+8%, +21%) and LV dilation (+20%), whereas B14G animals showed signs of decompensation with LV end-diastolic pressure increase (+167%) and mean arterial pressure decrease (-28%) associated with LV and RV hypertrophy (+77%, + 51%) and greater increases of LV and RV wall thickening (+19%, + 57%), as well as LV dilation (+43%). A 12G stenosis results in compensated hypertrophy at 60 and 120 d; a 14G stenosis leads to compensated hypertrophy at 60 d and heart failure at 120 d.

Prevalence and Pathophysiologic Attributes of Ventricular Dyssynchrony in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

This study sought to investigate the prevalence and mechanisms underlying right ventricular (RV) dyssynchrony in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) using tissue Doppler echocardiography (TDE). An ARVD/C is characterized by fibrofatty replacement of RV myocardium and RV dilation. These pathologic changes may result in electromechanical dyssynchrony. Echocardiography, both conventional and TDE, was performed in 52 ARVD/C patients fulfilling Task Force criteria and 25 control subjects. The RV end-diastolic and -systolic areas, right ventricular fractional area change (RVFAC), and left ventricular (LV) volumes and function were assessed. Mechanical synchrony was assessed by measuring differences in time-to-peak systolic velocity (T(SV)) between the RV free wall, ventricular septum, and LV lateral wall. An RV dyssynchrony was defined as the difference in T(SV) between the RV free wall and the ventricular septum, >2 SD above the mean value for control subjects. The mean difference in RV T(SV) was higher in ARVD/C compared with control subjects (55 +/- 34 ms vs. 26 +/- 15 ms, p < 0.001). Significant RV dyssynchrony was not noted in any of the control subjects. Based on a cutoff value of 56 ms, significant RV dyssynchrony was present in 26 ARVD/C patients (50%). Patients with RV dyssynchrony had a larger RV end-diastolic area (22 +/- 5 cm(2) vs. 19 +/- 4 cm(2), p = 0.02), and lower RVFAC (29 +/- 8% vs. 34 +/- 8%, p = 0.03) compared with ARVD/C patients without RV dyssynchrony. No differences in QRS duration, LV volumes, or function were present between the 2 groups. An RV dyssynchrony may occur in up to 50% of ARVD/C patients, and is associated with RV remodeling. This finding may have therapeutic and prognostic implications in ARVD/C.

Preserved cardiac synchrony and function with single-site left ventricular epicardial pacing during mid-term follow-up in paediatric patients

Right ventricular (RV) pacing may cause dyssynchronous left ventricular (LV) contraction and systolic dysfunction. Left ventricular-based pacing may prevent such deterioration. The aim of this study was to evaluate ventricular synchrony and function with permanent LV pacing (LVP) vs. RV pacing (RVP) in paediatric patients with normal cardiac anatomy. Twenty-five paediatric patients with normal cardiac anatomy and single-site epicardial RV apex pacing (RVP, n=10, pacing duration: 7.9+/-2.9 years) or LV free wall pacing (LVP, n=15, pacing duration: 4.3+/-2.6 years) for complete heart block were enrolled. A total of 15 healthy children served as a control group. Conventional echocardiography, myocardial circumferential (LV), and longitudinal (RV) 2D strain (2Ds) analysis were obtained. Paced QRS duration did not differ between groups (P=0.915). Interventricular mechanical delay (LVP: 17+/-10, RVP: 62+/-15 ms; P<0.0001), septal-to-posterior wall motion delay (LVP: 59+/-23, RVP: 294+/-84 ms; P<0.0001), septal-to-lateral wall motion delay (LVP: 40+/-19, RVP: 59+/-12 ms; P=0.009), and LV mechanical delay (LVP: 35+/-9, RVP: 63+/-17 ms; P<0.0001) were preserved for LVP but not for RVP. Right ventricular mechanical delay was similar among paced groups (P=0.639). Left ventricular ejection fraction was normal for LVP but not for RVP (LVP: 60+/-6%, RVP: 45+/-6%; P=0.012). Left ventricular pacing did not differ from controls for synchrony or function. Conventional and 2Ds echocardiographic measurements indicate preserved LV synchrony and function in paediatric patients with LVP compared with RVP. Permanent LVP has no impact on RV synchrony.

Ventricular interaction in children after repair of tetralogy of Fallot: a longitudinal echocardiographic study

Progressive right ventricular (RV) dilation due to pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) may impair left ventricular (LV) filling. Our aim was to analyse long-term time courses of M-mode LV and RV measurements and to relate these to the degree of PR. Retrospective longitudinal cohort of children (n = 88) after repair of TOF followed by serial echocardiography over 9 years. LV and RV diameters were expressed by z-scores based on normal paediatric reference values. Time courses of LV and RV diameter z-scores, degree of PR, and influence of co-variables were analysed using mixed regression models. LV diameter z-scores were significantly lowered before repair, increased after surgery, but fell again over time; thus, mean LV diameters were significantly lower than normal population means at all times. LV diameter z-scores correlated negatively with RV dilation and degree of PR. Notably, they were significantly higher in patients with previous shunts. After pulmonary valve replacement, LV diameter z-scores recovered to normal, whereas RV diameter z-scores remained abnormal. Our results confirm progressive adverse RV-LV interaction in the long-term post-operative follow-up of TOF. The use of z-scores facilitated the analysis of time courses of LV and RV diameters.

Reconstructed 4-chamber views compared with axial imaging for assessment of right ventricular enlargement on CT pulmonary angiograms

To test the hypothesis that right enlargement assessed from right ventricular/left ventricular (RV/LV) dimension ratios of computed tomographic (CT) angiograms are equivalent irrespective of whether measured on axial views or reconstructed 4-chamber views. RV/LV dimension ratios were calculated from measurements on axial views, manually reconstructed 4-chamber views and computer generated reconstructed 4-chamber views of CT angiograms in 152 patients with PE. Paired readings of the axial view and manually reconstructed 4-chamber view showed agreement with RV/LV > or =1 or RV/LV <1 in 114 of 127 (89.8%). Paired readings also showed agreement in 119 of 127 (93.7%) with axial views and computer generated reconstructed 4-chamber views. The McNemar test showed no statistically significant difference between assessments of RV enlargement (RV/LV > or = 1) with any method. Right ventricular enlargement can be determined from axial views on CT angiograms, which are readily and immediately available, without obtaining 4-chamber reconstructed views.

Intraoperative transesophageal echocardiography is beneficial for hemodynamic stabilization during left ventricular assist device implantation in children

Mechanical circulatory support, with a left ventricular assist device (LVAD) is used in an increasing number of children for treatment of advanced heart failure as bridge-to-transplant. To date no data are available and no studies have defined the role of intraoperative transesophageal echocardiography (TEE) for hemodynamic stabilization during Centrimag Levitronix centrifugal pump implantation in children. Children with therapy resistant heart failure, undergoing LVAD implantation using Berlin Heart Excor pediatric cannula connected to a Levitronix Centrifumag pump, are intraoperatively monitored using an Oldelft micromultiplane TEE. Intraoperative TEE is specially used to monitor right ventricular (RV) and left ventricular (LV) function, correct position of the cannulas and response to pharmacological treatment. In five consecutive patients RV function was assessed by TEE after starting LVAD Levitronix centrifugal pump. Initial RV failure presents with RV dilation and LV collapse. After titration of vasopressor and inotropic agents, RV contractility improved and thereby the filling of the LV. In one child, despite those measures the RV showed no improvement by TEE and a Levitronix right ventricular assist device to support the RV function was implanted as well. All patients could hemodynamically be stabilized before transport to the intensive care unit. The complex interaction of the RV and LV function and correct positioning of the cannula, during LVAD implantation in children with end-stage cardiac failure is improved by simultaneous visualization of cardiac performance of both ventricles and cannula positioning by means of intraoperative multiplane TEE.