Bariatric surgery mitigated electrocardiographic abnormalities in patients with morbid obesity

Obesity can lead to cardiovascular dysfunctions and cause electrocardiographic disruptions. Bariatric surgery plays a significant role in weight loss. To assess its benefits, this study investigated electrocardiographic changes before and after bariatric surgery. The present article describes a retrospective cohort study with a 6-month follow-up period. Electrocardiograms were interpreted and compared before and six months after surgery. The relationships between weight loss, type of surgery, and electrocardiographic alterations were analyzed. A total of 200 patients participated in the study, with 34 (17%) men and 166 (83%) women. The mean age of the participants was 44.6 ± 8.6, and their mean body mass index was 43.8 ± 5.5 kg/m2. The mean of QTc decreased after the surgery, while the Sokolow-Lyon scores increased. The statistical analysis showed that QTc dispersion (> 40) (P < 0.001), right ventricular hypertrophy (P < 0.001), abnormal R wave progression (P < 0.001), QTc (P < 0.001) and Sokolow-Lyon criteria (P < 0.001) significantly changed postoperatively. In conclusion, bariatric surgery can reduce QTc, correct poor R wave progression, and resolve right ventricular hypertrophy (RVH) in patients with morbid obesity.

Analysis of QRS complex morphology in children and adolescents with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) leads to many cardiovascular, neurologic, metabolic, and neurocognitive consequences. Conduction deficits, deviations in electrical axis, and changes in QRS morphology reflect the impairments in cardiac muscle activity and underlie the cardiovascular complications of OSAS. Here we aimed to determine the relationship between OSAS and changes in the cardiac conduction system in children and adolescents. During the 6-month duration of the study, all children having the diagnosis of OSAS in Sleep and Disorders Unit following a full-night polysomnography (PSG) were consecutively evaluated. ECGs were performed and analyzed in the Division of Pediatric Cardiology, Department of Pediatrics. The maximum spatial vector size (QRSmax), QRS electrical axis (EA), left and right ventricular hypertrophy, and the presence of fragmented QRS (fQRS) or prolonged R or S wave were examined in detail. A total of 17 boys with OSAS and 13 healthy boys participated in the study. The mean QRSmax and the QRSmax on V5 derivative were significantly lower in the patient group compared to those in the control group (p = 0.011 and p = 0.017, respectively). EA was similar between the two groups. While none of the patients with OSAS nor the control group had left ventricular hypertrophy, only one boy with OSAS had right ventricular hypertrophy according to ECG-derived analysis. The percentage of fQRS or notched R or S waves was significantly higher in patients with OSAS compared to healthy controls (p = 0.035), especially in children below the age of 5 years (p = 0.036).  Conclusion: This study demonstrated that male children and adolescents with OSAS have a combination of QRS complex changes characterized by low QRS voltages, and increased frequency of fragmented QRS. These findings reflect that the electrical remodeling and structural remodeling of the myocardium are considerably affected by OSAS in children and adolescents, leading to ventricular changes and intraventricular conduction problems. What is Known: • Pediatric obstructive sleep apnea syndrome (OSAS) characterized by recurrent intermittent hypoxemia, hypercapnia, and sleep fragmentation results in sympathetic nervous system activation, increased inflammation, and hypoxic endothelial dysfunction. When left untreated, OSAS leads to many cardiovascular, neurologic, metabolic and neurocognitive consequences, and also to sudden infant death syndrome in young children, probably due to the involvement of the cardiac conduction system. What is New: • This study demonstrated that mean QRSmax was significantly lower in male children and adolescents with OSAS, reflecting the structural and electrical remodeling of the myocardium, and one boy with OSAS had RVH according to ECG-derived analysis. The percentage of fQRS or notched R or S waves was much higher in boys with OSAS, especially in children below the age of five years. These finding showed that myocardium was considerably affected to impair the intraventricular conduction in younger children with OSAS.

Role of Oxygen Starvation in Right Ventricular Decompensation and Failure in Pulmonary Arterial Hypertension

Right ventricular (RV) function and eventually failure determine outcome in patients with pulmonary arterial hypertension (PAH). Initially, RV responds to an increased load caused by PAH with adaptive hypertrophy; however, eventually RV failure ensues. Unfortunately, it is unclear what causes the transition from compensated RV hypertrophy to decompensated RV failure. Moreover, at present, there are no therapies for RV failure; those for left ventricular (LV) failure are ineffective, and no therapies specifically targeting RV are available. Thus there is a clear need for understanding the biology of RV failure and differences in physiology and pathophysiology between RV and LV that can ultimately lead to development of such therapies. In this paper, we discuss RV adaptation and maladaptation in PAH, with a particular focus of oxygen delivery and hypoxia as the principal drivers of RV hypertrophy and failure, and attempt to pinpoint potential sites for therapy.

Thioredoxin system activation is associated with the progression of experimental pulmonary arterial hypertension

In addition to being an antioxidant, thioredoxin (Trx) is known to stimulate signaling pathways involved in cell proliferation and to inhibit apoptosis. The aim of this study was to explore the role of Trx in some of these pathways along the progression of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male rats were first divided into two groups: monocrotaline (MCT - 60 mg/kg i.p.) and control (received saline), that were further divided into three groups: 1, 2, and 3 weeks. Animals were submitted to echocardiographic analysis. Right and left ventricles were used for the measurement of hypertrophy, through morphometric and histological analysis. The lung was prepared for biochemical and molecular analysis. One week after MCT injection, there was an increase in thioredoxin reductase (TrxR) activity, a reduction in glutathione reductase (GR) activity, and an increase in Trx-1 and vitamin D3 up-regulated protein-1 (VDUP-1) expression. Two weeks after MCT injection, there was an increase in VDUP-1, Akt and cleaved caspase-3 activation, and a decrease in Trx-1 and Nrf2 expression. PAH-induced by MCT promoted a reduction in Nrf2 and Trx-1 expression as well as an increase in Akt and VDUP-1 expression after three weeks. The increase in pulmonary vascular resistance was accompanied by increased TrxR activity, suggesting an association between the Trx system and functional changes in the progression of PAH. It seems that Trx-1 activation was an adaptive response to MCT administration to cope with pulmonary remodeling and disease progression, suggesting a potential new target for PAH therapeutics.

The Short-Chain Fatty Acid Butyrate Attenuates Pulmonary Vascular Remodeling and Inflammation in Hypoxia-Induced Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive cardiovascular disorder in which local vascular inflammation leads to increased pulmonary vascular remodeling and ultimately to right heart failure. The HDAC inhibitor butyrate, a product of microbial fermentation, is protective in inflammatory intestinal diseases, but little is known regarding its effect on extraintestinal diseases, such as PH. In this study, we tested the hypothesis that butyrate is protective in a Sprague-Dawley (SD) rat model of hypoxic PH. Treatment with butyrate (220 mg/kg intake) prevented hypoxia-induced right ventricular hypertrophy (RVH), hypoxia-induced increases in right ventricular systolic pressure (RVSP), pulmonary vascular remodeling, and permeability. A reversal effect of butyrate (2200 mg/kg intake) was observed on elevated RVH. Butyrate treatment also increased the acetylation of histone H3, 25-34 kDa, and 34-50 kDa proteins in the total lung lysates of butyrate-treated animals. In addition, butyrate decreased hypoxia-induced accumulation of alveolar (mostly CD68+) and interstitial (CD68+ and CD163+) lung macrophages. Analysis of cytokine profiles in lung tissue lysates showed a hypoxia-induced upregulation of TIMP-1, CINC-1, and Fractalkine and downregulation of soluble ICAM (sICAM). The expression of Fractalkine and VEGFα, but not CINC-1, TIMP-1, and sICAM was downregulated by butyrate. In rat microvascular endothelial cells (RMVEC), butyrate (1 mM, 2 and 24 h) exhibited a protective effect against TNFα- and LPS-induced barrier disruption. Butyrate (1 mM, 24 h) also upregulated tight junctional proteins (occludin, cingulin, claudin-1) and increased the acetylation of histone H3 but not α-tubulin. These findings provide evidence of the protective effect of butyrate on hypoxic PH and suggest its potential use as a complementary treatment for PH and other cardiovascular diseases.

Perillyl alcohol suppresses monocrotaline-induced pulmonary arterial hypertension in rats via anti-remodeling, anti-oxidant, and anti-inflammatory effects

Background: Pulmonary arterial hypertension (PAH) is a disastrous disease that current treatments cannot prevent its progression. The present study investigated the effects of perillyl alcohol (PA), a natural monoterpene, on the experimental PAH in male Wistar rats. Methods: Rats divided into eight groups of control, Monocrotaline (MCT), MCT+vehicle, and MCT+PA with doses of 20, 30, 40, 50, and 60 mg/kg. PAH was induced by a single injection of monocrotaline (60 mg/kg) on day 0. The animals in the groups of MCT+vehicle and MCT+PA received the vehicle or PA from day 22 to 42 once a day. On day 43, under general anesthesia, right ventricular systolic pressure (RVSP), as an index of pulmonary artery systolic pressure, and the ratio of the right ventricle to the left ventricle plus septum weight, as the right ventricular hypertrophy index (RVHI), were measured. Also, some histological and biochemical indices were assessed in the lung tissue. Results: MCT significantly (p < .001) enhanced the RVSP and RVHI compared to the control group (89.4 ± 8.2 vs 23 ± 3.3 mmHg & 0.63 ± 0.08 vs 0.26 ± 0.04 respectively). It also increased oxidative stress and inflammatory cytokines and reduced Bax/Bcl2 ratio. Treatment with PA significantly recovered RVSP and hypertrophy index and suppressed vascular cell proliferation, oxidant production, and inflammatory processes. Conclusion: PA exerted noticeable protective and curative effects against MCT-induced PAH and pulmonary vascular remodeling through inhibiting cellular proliferation, oxidative stress, and inflammation. Therefore, PA can be considered as a new therapeutic goal for the treatment of PAH.

S-Nitroso-L-Cysteine Ameliorated Pulmonary Hypertension in the MCT-Induced Rats through Anti-ROS and Anti-Inflammatory Pathways

Pulmonary hypertension (PH) is a progressive and life-threatening chronic disease in which increased pulmonary artery pressure (PAP) and pulmonary vasculature remodeling are prevalent. Inhaled nitric oxide (NO) has been used in newborns to decrease PAP in the clinic; however, the effects of NO endogenous derivatives, S-nitrosothiols (SNO), on PH are still unknown. We have reported that S-nitroso-L-cysteine (CSNO), one of the endogenous derivatives of NO, inhibited RhoA activity through oxidative nitrosation of its C16/20 residues, which may be beneficial for both vasodilation and remodeling. In this study, we presented data to show that inhaled CSNO attenuated PAP in the monocrotaline- (MCT-) induced PH rats and, moreover, improved right ventricular (RV) hypertrophy and fibrosis induced by RV overloaded pressure. In addition, aerosolized CSNO significantly inhibited the hyperactivation of signal transducers and activators of transduction 3 (STAT3) and extracellular regulated protein kinases (ERK) pathways in the lung of MCT-induced rats. CSNO also regulated the expression of smooth muscle contractile protein and improved aberrant endoplasmic reticulum (ER) stress and mitophagy in lung tissues following MCT induction. On the other hand, CSNO inhibited reactive oxygen species (ROS) production in vitro, which is induced by angiotensin II (AngII) as well as interleukin 6 (IL-6). In addition, CSNO inhibited excessive ER stress and mitophagy induced by AngII and IL-6 in vitro; finally, STAT3 and ERK phosphorylation was inhibited by CSNO in a concentration-dependent manner. Taken together, CSNO led to pulmonary artery relaxation and regulated pulmonary circulation remodeling through anti-ROS and anti-inflammatory pathways and may be used as a therapeutic option for PH treatment.

Coconut Oil Aggravates Pressure Overload-Induced Cardiomyopathy without Inducing Obesity, Systemic Insulin Resistance, or Cardiac Steatosis

Studies evaluating the effects of high-saturated fat diets on cardiac function are most often confounded by diet-induced obesity and by systemic insulin resistance. We evaluated whether coconut oil, containing C12:0 and C14:0 as main fatty acids, aggravates pressure overload-induced cardiomyopathy induced by transverse aortic constriction (TAC) in C57BL/6 mice. Mortality rate after TAC was higher (p < 0.05) in 0.2% cholesterol 10% coconut oil diet-fed mice than in standard chow-fed mice (hazard ratio 2.32, 95% confidence interval 1.16 to 4.64) during eight weeks of follow-up. The effects of coconut oil on cardiac remodeling occurred in the absence of weight gain and of systemic insulin resistance. Wet lung weight was 1.76-fold (p < 0.01) higher in coconut oil mice than in standard chow mice. Myocardial capillary density (p < 0.001) was decreased, interstitial fibrosis was 1.88-fold (p < 0.001) higher, and systolic and diastolic function was worse in coconut oil mice than in standard chow mice. Myocardial glucose uptake was 1.86-fold (p < 0.001) higher in coconut oil mice and was accompanied by higher myocardial pyruvate dehydrogenase levels and higher acetyl-CoA carboxylase levels. The coconut oil diet increased oxidative stress. Myocardial triglycerides and free fatty acids were lower (p < 0.05) in coconut oil mice. In conclusion, coconut oil aggravates pressure overload-induced cardiomyopathy.

[INFLUENCE OF THE FEMALE SEX HORMONE 17-BETA-ESTRADIOL ON THE DEGREE OF HYPOXIC PULMONARY HYPERTENSION IN MALE AND FEMALE WISTAR RATS.]

The influence of endogenous and exogenous 17-beta-estradiol on the degree of hypoxic pulmonary hypertension (HPH) in male and female Wistar rats has been studied. Endogenous estradiol reduced the right ventricular systolic pressure (RVSP) in normal female rats, but not in male rats. Exogenous estradiol (15 pg/kg for 4 weeks) caused the same effect. The HPH was induced by exposure to intermittent hypobaric hypoxia (10 h a day, 02 = 10%). Two weeks after hypoxia exposure, increased RVSP was more developed in females as compared to males. Comparison of RVSP between hypertensive and normotensive fet'a- le groups showed that the pathology in hypertensive females with retained ovaries is developed more than in ovariectomized ones. Exogenous estradiol exhibi- ted no protective effect in hypoxic ovariectomized female rats. In males, the ovariectomy did not influence the RVSP level, but caused hypertrophy of the right ventricle. In this case, exogenous estradiol led to an increase in RVSP. Thus, endogenous 17-beta-estradiol has a protective effect on the pulmonary blood flow in normal females. In the case of hypoxic pulmonary hypertension, endogenous estradiol enhances the development of this pathology in females and ovariecto- mized males.

[Study on tissue Doppler imaging in diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease]

OBJECTIVE

To investigate the value of tissue Doppler imaging (TDI) in the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease.

METHODS

A total of 50 cases of silicosis complicated by chronic pulmonary heart disease in our hospital underwent conventional electrocardiography (ECG) and TDI. The detection rates for right ventricular hypertrophy by two methods were compared.

RESULTS

Of 50 cases of silicosis complicated by chronic pulmonary heart disease, 19 were diagnosed with right ventricular hypertrophy by ECG, with a detection rate of 38.0%; 29 were diagnosed with right ventricular hypertrophy by TDI, with a detection rate off 58.0%. Statistical analysis suggested that TDI leads to a significantly higher detection rate for right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease (χ² = 4.006, P = 0.036).

CONCLUSION

Both TDI and ECG can be used for detecting right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease, but the detection rate is higher when TDI is employed. In addition, ECG cannot directly reflect the increase in pulmonary artery pressure. Therefore, TDI is more suitable for the diagnosis of right ventricular hypertrophy in patients with silicosis complicated by chronic pulmonary heart disease and provides a strong diagnostic basis for the clinical treatment of silicosis complicated by pulmonary heart disease.

Pulmonary hypertension in wild type mice and animals with genetic deficit in KCa2.3 and KCa3.1 channels

Objective

In vascular biology, endothelial K_Ca2.3 and K_Ca3.1 channels contribute to arterial blood pressure regulation by producing membrane hyperpolarization and smooth muscle relaxation. The role of K_Ca2.3 and K_Ca3.1 channels in the pulmonary circulation is not fully established. Using mice with genetically encoded deficit of K_Ca2.3 and K_Ca3.1 channels, this study investigated the effect of loss of the channels in hypoxia-induced pulmonary hypertension.

Approach and Result

Male wild type and K_Ca3.1^−/−/K_Ca2.3^T/T(+DOX) mice were exposed to chronic hypoxia for four weeks to induce pulmonary hypertension. The degree of pulmonary hypertension was evaluated by right ventricular pressure and assessment of right ventricular hypertrophy. Segments of pulmonary arteries were mounted in a wire myograph for functional studies and morphometric studies were performed on lung sections. Chronic hypoxia induced pulmonary hypertension, right ventricular hypertrophy, increased lung weight, and increased hematocrit levels in either genotype. The K_Ca3.1^−/−/K_Ca2.3^T/T(+DOX) mice developed structural alterations in the heart with increased right ventricular wall thickness as well as in pulmonary vessels with increased lumen size in partially- and fully-muscularized vessels and decreased wall area, not seen in wild type mice. Exposure to chronic hypoxia up-regulated the gene expression of the K_Ca2.3 channel by twofold in wild type mice and increased by 2.5-fold the relaxation evoked by the K_Ca2.3 and K_Ca3.1 channel activator NS309, whereas the acetylcholine-induced relaxation - sensitive to the combination of K_Ca2.3 and K_Ca3.1 channel blockers, apamin and charybdotoxin - was reduced by 2.5-fold in chronic hypoxic mice of either genotype.

Conclusion

Despite the deficits of the K_Ca2.3 and K_Ca3.1 channels failed to change hypoxia-induced pulmonary hypertension, the up-regulation of K_Ca2.3-gene expression and increased NS309-induced relaxation in wild-type mice point to a novel mechanism to counteract pulmonary hypertension and to a potential therapeutic utility of K_Ca2.3/K_Ca3.1 activators for the treatment of pulmonary hypertension.

Muscle RING finger-1 promotes a maladaptive phenotype in chronic hypoxia-induced right ventricular remodeling

Exposure to chronic hypoxia (CH) induces elevated pulmonary artery pressure/resistance, leading to an eventual maladaptive right ventricular hypertrophy (RVH). Muscle RING finger-1 (MuRF1) is a muscle-specific ubiquitin ligase that mediates myocyte atrophy and has been shown to play a role in left ventricular hypertrophy and altered cardiac bioenergetics in pressure overloaded hearts. However, little is known about the contribution of MuRF1 impacting RVH in the setting of CH. Therefore, we hypothesized that MuRF1 deletion would enhance RVH compared to their wild-type littermates, while cardiac-specific overexpression would reduce hypertrophy following CH-induced pulmonary hypertension. We assessed right ventricular systolic pressure (RVSP), right ventricle to left ventricle plus septal weight ratio (RV/LV+S) and hematocrit (Hct) following a 3-wk isobaric CH exposure. Additionally, we conducted dual-isotope SPECT/CT imaging with cardiac function agent ²⁰¹Tl-chloride and cell death agent ^99mTc-annexin V. Predictably, CH induced pulmonary hypertension, measured by increased RVSP, RV/LV+S and Hct in WT mice compared to normoxic WT mice. Normoxic WT and MuRF1-null mice exhibited no significant differences in RVSP, RV/LV+S or Hct. CH-induced increases in RVSP were also similar between WT and MuRF1-null mice; however, RV/LV+S and Hct were significantly elevated in CH-exposed MuRF1-null mice compared to WT. In cardiac-specific MuRF1 overexpressing mice, RV/LV+S increased significantly due to CH exposure, even greater than in WT mice. This remodeling appeared eccentric, maladaptive and led to reduced systemic perfusion. In conclusion, these results are consistent with an atrophic role for MuRF1 regulating the magnitude of right ventricular hypertrophy following CH-induction of pulmonary hypertension.

[Changes of the hemodynamics, heart structure and functional state in patients with reactive arthritis]

Our investigation showed for the patients with reactive arthritis typical is hyperkinetic type of haemodynamic, and also structural changes of the heart which manifestate by interventricular partition's thickness as a result of inflammatory edema and it's valve consolidation frequently whithout expressed blood regurgitation, and diastolic dysfunction's development of the left and right heart ventricles in hypertrophic type with disorders of their active relaxation and growth their chamber's rigidity. These changes, probably, evidence about development of the inflammatory cardiopathy in these patients and can be preconditions of the heart failure.

Right ventricular pacing for right ventricular outflow tract obstruction in a man with biventricular hypertrophic cardiomyopathy

WEBSITE FEATURE

Cardiomyocyte-specific overexpression of HEXIM1 prevents right ventricular hypertrophy in hypoxia-induced pulmonary hypertension in mice

Right ventricular hypertrophy (RVH) and right ventricular (RV) contractile dysfunction are major determinants of prognosis in pulmonary arterial hypertension (PAH) and PAH remains a severe disease. Recently, direct interruption of left ventricular hypertrophy has been suggested to decrease the risk of left-sided heart failure. Hexamethylene bis-acetamide inducible protein 1 (HEXIM1) is a negative regulator of positive transcription elongation factor b (P-TEFb), which activates RNA polymerase II (RNAPII)-dependent transcription and whose activation is strongly associated with left ventricular hypertrophy. We hypothesized that during the progression of PAH, increased P-TEFb activity might also play a role in RVH, and that HEXIM1 might have a preventive role against such process. We revealed that, in the mouse heart, HEXIM1 is highly expressed in the early postnatal period and its expression is gradually decreased, and that prostaglandin I(2), a therapeutic drug for PAH, increases HEXIM1 levels in cardiomyocytes. These results suggest that HEXIM1 might possess negative effect on cardiomyocyte growth and take part in cardiomyocyte regulation in RV. Using adenovirus-mediated gene delivery to cultured rat cardiomyocytes, we revealed that overexpression of HEXIM1 prevents endothelin-1-induced phosphorylation of RNAPII, cardiomyocyte hypertrophy, and mRNA expression of hypertrophic genes, whereas a HEXIM1 mutant lacking central basic region, which diminishes P-TEFb-suppressing activity, could not. Moreover, we created cardiomyocyte-specific HEXIM1 transgenic mice and revealed that HEXIM1 ameliorates RVH and prevents RV dilatation in hypoxia-induced PAH model. Taken together, these findings indicate that cardiomyocyte-specific overexpression of HEXIM1 inhibits progression to RVH under chronic hypoxia, most possibly via inhibition of P-TEFb-mediated enlargement of cardiomyocytes. We conclude that P-TEFb/HEXIM1-dependent transcriptional regulation may play a pathophysiological role in RVH and be a novel therapeutic target for mitigating RVH in PAH.

Differential responses of the right ventricle to abnormal loading conditions in mice: pressure vs. volume load

AIMS

Right ventricular (RV) dysfunction is a major determinant of long-term morbidity and mortality in congenital heart disease. The right ventricle (RV) is genetically different from the left ventricle (LV), but it is unknown as to whether this has consequences for the cellular responses to abnormal loading conditions. In the LV, calcineurin-activation is a major determinant of pathological hypertrophy and an important target for therapeutic strategies. We studied the functional and molecular adaptation of the RV in mouse models of pressure and volume load, focusing on calcineurin-activation.

METHODS AND RESULTS

Mice were subjected to pulmonary artery banding (PAB), aorto-caval shunt (Shunt), or sham surgery (Control). Four weeks later, mice were functionally evaluated with cardiac magnetic resonance imaging, pressure measurements, and voluntary cage wheel exercise. Right ventricular hypertrophy and calcineurin-activation were assessed after sacrifice. Mice with increased pressure load (PAB) or volume load (Shunt) of the RV developed similar degrees of hypertrophy, yet revealed different functional and molecular adaptation. Pulmonary artery banding increased expression of Modulatory-Calcineurin-Interacting-Protein 1 (MCIP1), indicating calcineurin-activation, and the ratio of beta/alpha-Myosin Heavy Chain (MHC). In addition, PAB reduced exercise capacity and induced moderate RV dilatation with normal RV output at rest. In contrast, Shunt did not increase MCIP1 expression, and only moderately increased beta/alpha-MHC ratio. Shunt did not affect exercise capacity, but increased RV volumes and output at rest.

CONCLUSIONS

Pressure and volume load induced different functional and molecular adaptations in the RV. These results may have important consequences for therapeutic strategies to prevent RV failure in the growing population of adults with congenital heart disease.

Isolated right ventricular hypertrophic obstructive cardiomyopathy

A case of isolated right ventricular hypertrophic obstructive cardiomyopathy without left ventricular involvement is reported. This is a rare cause of isolated right ventricular strain and needs to be differentiated form ventricular septal defect and pulmonary valve stenosis.

Sickle cell lung disease and sudden death: a retrospective/prospective study of 21 autopsy cases and literature review

Sudden death in the setting of sickle cell lung disease (SCLD), is periodically seen in the practice of medical examiners. The goal of the present study was to identify the most common pathologic findings of SCLD associated with sudden or unexpected death. A retrospective/prospective review of 21 autopsy cases from sickle cell patients between 1990 and 2004 was performed. Review of medical records, autopsy reports, and H&E-stained slides of lung tissue was performed. Oil-Red-O and elastic staining of lung tissue were evaluated. All cases were screened for both acute and chronic forms of SCLD. Patients admitted for sickle cell pain crisis ranged in age from 8 months to 65 years. Fifteen out of 21 cases (71.4%) showed significant pulmonary pathology. The most frequent lung findings included pulmonary edema (47.6%), pulmonary thromboembolism (38.1%), fat emboli (33.3%), pulmonary hypertension, grades I-IV (33.3%), and microvascular occlusive thrombi (28.5%). Our study demonstrates higher-than-expected percentages of acute and chronic sickle cell-related lung injury such as fat embolism (33.3%) and pulmonary hypertension (33.3%), with right ventricular hypertrophy (33.3%). Therefore, we propose a simple and high-yield autopsy algorithm of ancillary procedures that should be applied on all known and suspected autopsy cases of sickle cell disease.

Noninvasive Assessment of Pulmonary Arterial Capacitance by Echocardiography

BACKGROUND

Pulmonary arterial capacitance (PAC) has been associated with right ventricular (RV) workload and mortality in pulmonary hypertension, but is not routinely evaluated in children. We investigated whether PAC can be estimated noninvasively by echocardiography.

METHODS

We retrospectively determined PAC in 31 children with pulmonary hypertension, using echocardiography, and compared the results with those obtained at cardiac catheterization.

RESULTS

PAC derived from echocardiography was similar to that derived from catheterization (mean +/- SD 1.16 +/- 1.0 vs 1.10 +/- 0.95 mL(3) x mm Hg(-1), P = not significant) and the two correlated well (r = 0.74, P < .0001). There was a highly significant polynomial relationship between PAC and RV anterior wall thickness indexed to body surface area (R(2) = 0.54, P < .0001), but not between pulmonary vascular resistance and RV wall thickness. Pulmonary vascular resistance and PAC did not correlate.

CONCLUSIONS

Echocardiography can reliably estimate PAC, which strongly correlates with RV hypertrophy, a surrogate for RV work.

Intracardiac thrombus and pulmonary embolism with cavitation and pneumomediastinum in a patient with protein S deficiency

We present a case of intracardiac thrombus with pulmonary embolism and pulmonary infarction in a patient with protein S deficiency. Secondary infection of the pulmonary infarction resulted in pneumomediastinum. Thrombus in an unusual location in a young patient without known predisposing conditions is a characteristic feature of a hereditary thrombophilic disorder. Cavitation within a lesion adjacent to the mediastinal pleura can result in pneumomediastinum.

Pathologic and molecular analysis in a family with rare mixed supravalvar aortic and pulmonic stenosis

Nonsyndromic supravalvar aortic stenosis (SVAS) is an obstructive vascular disorder often inherited in an autosomal dominant manner. With pulmonary artery involvement, stenotic lesions are nearly always peripheral or downstream of the pulmonic valve. In rare cases when the supravalvar pulmonic region is affected, the stenoses usually improve over time and rarely affect prognosis. We evaluated a unique family in which 10 of 14 individuals have nonsyndromic SVAS and 7 of the 10 affected family members with SVAS have the rare finding of supravalvar pulmonic stenosis (SVPS). In at least 2 of these individuals, the severity of SVPS was so significant that it led to death in early infancy. Pathologic examination of stenotic lesions in this kindred group revealed concentrically organized smooth muscle cells separated by dense elastic fibers. In contrast, the arterial pathology reported for other individuals with nonsyndromic SVAS demonstrates increased numbers of hypertrophied smooth muscle cells separated by thin, fragmented elastin fibers. Molecular analysis identified a novel ELN mutation within the donor splice site of exon 16, which may be responsible for the unique phenotype and distinct elastin histopathology found in this kindred.

The roles of chronic pressure and volume overload states in induction of arrhythmias: An animal model of physiologic sequelae after repair of tetralogy of Fallot

OBJECTIVE

Sudden death occurs in as many as 8% of patients after repair of tetralogy of Fallot and has been attributed to arrhythmias. The purpose of this study was to establish an animal model to evaluate the individual contribution of different physiologic sequelae after tetralogy of Fallot repair in the development of late-onset arrhythmias.

METHODS

Forty-nine piglets were divided into 5 groups: (1) pulmonary artery band; (2) pulmonary valvotomy; (3) pulmonary artery band plus pulmonary valvotomy; (4) infundibular scar; and (5) age-matched control animals. Baseline and follow-up electrocardiograms were obtained and recorded, as well as changes in QRS duration. A total of 45 animals underwent hemodynamic evaluation and programmed electrical stimulation at 5.6 months postoperatively.

RESULTS

Sustained ventricular tachyarrhythmias (ventricular tachycardia/ventricular fibrillation) were induced in 31.1%, and atrial arrhythmias were induced in 33.3%. The pulmonary valvotomy group was 30 times more likely to evidence arrhythmias than control animals for sustained ventricular tachycardia/ventricular fibrillation, as well as atrial arrhythmias (P = .01). The pulmonary artery band group was 15 times more likely to evidence atrial arrhythmias than control animals (P = .02). Prolonged QRS duration was predictive of inducibility of both atrial arrhythmias (P < .01) and sustained ventricular tachycardia/ventricular fibrillation (P = .01). Mean right atrial (P = .01) and capillary wedge (P = .01) pressures predicted atrial arrhythmia inducibility. Right ventricular end-diastolic pressure predicted atrial arrhythmia (P= .01) and sustained ventricular tachycardia/ventricular fibrillation inducibility (P = .05). Right ventricular systolic pressure did not predict inducibility of either atrial arrhythmias (P = .10) or sustained ventricular tachycardia/ventricular fibrillation (P = .94).

CONCLUSIONS

Chronic right ventricular volume overload resulted in an increased incidence of inducible ventricular and atrial arrhythmias.

Phosphodiesterase type 5 and high altitude pulmonary hypertension

BACKGROUND

This study explored phosphodiesterase type 5 (PDE5) inhibition as a strategy for treating high altitude pulmonary arterial hypertension (HAPH).

METHODS

689 subjects (313 men) of mean (SD) age 44 (0.6) years living above 2500 m were screened for HAPH by medical examination and electrocardiography, and 188 (27%) met the criteria for right ventricular hypertrophy. 44 underwent cardiac catheterisation and 29 (66%) had a resting mean pulmonary artery pressure (PAP) above 25 mmHg. 22 patients with a raised mean PAP were randomised to receive sildenafil (25 or 100 mg) or matching placebo taken 8 hourly for 12 weeks.

RESULTS

At 3 months, patients on sildenafil 25 mg 8 hourly (n = 9) had a significantly (p = 0.018) lower mean PAP (-6.9 mmHg) at the end of the dosing interval than those on placebo (n = 8) (95% CI -12.4 to -1.3). The treatment effect for sildenafil 100 mg 8 hourly (n = 5) compared with placebo was -6.4 mm Hg (95% CI -12.9 to 0.1). Both doses improved 6 minute walk distance, the lower dose by 45.4 m (95% CI 11.5 to 79.4; p = 0.011) and the higher dose by 40.0 m (95% CI 0.2 to 79.8; p = 0.049). Sildenafil was well tolerated. Necroscopic lung specimens from three subjects with HAPH showed abundant PDE5 in the muscular coat of remodelled pulmonary arterioles.

CONCLUSIONS

PDE5 is an attractive drug target for the treatment of HAPH and a larger study of the long term effects of PDE5 inhibition in HAPH is warranted.

Isquemia de ventrículo derecho y cor pulmonale

48 year old man with chronic obstructive pulmonary disease (COPD) secondary to pulmonary hypertension with domiciliary non-invasive ventilation was seen. He came to the emergency department with acute exacerbation of COPD. The patient was admitted to the Cardiology Service with the diagnosis of congestive heart failure. Diagnostic imaging (chest X-ray, transthoracic Doppler-echocardiography, multidetector row spiral CT and myocardial perfusion imaging) revealed an enlarged right ventricle. ECG was consistent with right ventricular failure. The heart perfusion imaging (pharmacologic stress testing with dobutamine) showed cor pulmonale and right ventricle ischemia induced by drug stress with dobutamine. Although right ventricle myocardial chronic dysfunction rarely causes right ventricular failure, it can occur when cor pulmonale and ischemia heart disease are present.

Early changes of cardiac structure and function in COPD patients with mild hypoxemia

BACKGROUND

COPD is often associated with changes of the structure and the function of the heart. Although functional abnormalities of the right ventricle (RV) have been well described in COPD patients with severe hypoxemia, little is known about these changes in patients with normoxia and mild hypoxemia.

STUDY OBJECTIVES

To assess the structural and functional cardiac changes in COPD patients with normal Pa(O2) and without signs of RV failure.

METHODS

In 25 clinically stable COPD patients (FEV1, 1.23 +/- 0.51 L/s; Pa(O2), 82 +/- 10 mm Hg [mean +/- SD]) and 26 age-matched control subjects, the RV and left ventricular (LV) structure and function were measured by MRI. Pulmonary artery pressure (PAP) was estimated from right pulmonary artery distensibility.

RESULTS

RV mass divided by RV end-diastolic volume as a measure of RV adaptation was 0.72 +/- 0.18 g/mL in the COPD group and 0.41 +/- 0.09 g/mL in the control group (p < 0.01). LV and RV ejection fractions were 62 +/- 14% and 53 +/- 12% in the COPD patients, and 68 +/- 11% and 53 +/- 7% in the control subjects, respectively. PAP estimated from right pulmonary artery distensibility was not elevated in the COPD group.

CONCLUSION

From these results, we conclude that concentric RV hypertrophy is the earliest sign of RV pressure overload in patients with COPD. This structural adaptation of the heart does not alter RV and LV systolic function.

The right ventricle in Fabry disease

AIM

Left ventricular (LV) hypertrophy is a common feature in Fabry disease-related progressive infiltrative hypertrophic cardiomyopathy and affects both men and women, but at different ages. To date, however, little is known about the role of right ventricular (RV) function in Fabry disease. Therefore, this study aimed to investigate the extent of RV involvement in patients with Fabry disease.

METHODS

Echocardiographic examination of the right and left ventricle was carried out in 129 patients (80 women and 49 men) with Fabry disease.

RESULTS

RV hypertrophy was present in 46 patients (35.7%). Of these patients, 13 showed signs of severely depressed right systolic function (tricuspid annulus movement < 10 mm and a prolonged RV pre-ejection period/pulmonary ejection time ratio) and six patients showed additional severe depression of parameters of diastolic function (pseudo-normal or restrictive RV filling pattems). Those patients with RV hypertrophy and severely compromised systolic and diastolic function had the highest LV masses (92 +/- 11.7 g/m(2.7)).

CONCLUSION

RV involvement is common in Fabry disease and ultimately progresses to severe systolic and diastolic RV dysfunction. These findings might explain why patients with preserved LV function can develop clinical features such as reduced exercise capacity, organomegaly and lymphoedema.

The role of 5-hydroxytryptamine in the control of pulmonary vascular tone in a rabbit model of pulmonary hypertension secondary to left ventricular dysfunction

The role of 5-hydroxytryptamine (5-HT) in a rabbit model of pulmonary hypertension (PHT) secondary to left ventricular dysfunction was investigated. Following pulmonary artery catheterisation under anaesthesia, 5-HT (1-400 microg kg(-1) i.v.) was administered before and after either 5-HT(2A) receptor antagonism with ketanserin (0.5 mg kg(-1)) or infusion of the nitric oxide synthase inhibitor, l-NAME (30 micromol min(-1)). Eight week coronary artery ligated rabbits demonstrate increased mean pulmonary arterial pressure (PAP) compared to controls (17.0+/-0.5 versus 12.0+/-0.5 mmHg, P<0.001) accompanied by right ventricular hypertrophy. 5-HT alone produced a greater pulmonary pressor response in rabbits with PHT (increase of 7.5+/-1.2, n=12 c.f. 3.5+/-0.4 mmHg in shams, n=12, P<0.01). Ketanserin had no effect on basal PAP in either PHT or control rabbits but inhibited the response to 5-HT in both groups. The response to 5-HT following l-NAME was increased in both groups and was greater in rabbits with PHT (an increase of 20.1+/-2.9, n=6 c.f. 11.4+/-1.8 mmHg, n=6, P<0.05). These results suggest that the difference shown in the in vivo pulmonary response to exogenous 5-HT is mediated largely through 5-HT(2A) receptors in this model. However, activity of endogenous 5-HT at the 5-HT(2A) receptors is not responsible for maintaining the raised basal PAP through vasoconstriction in PHT rabbits once PHT has developed.

Effect of nolomirole on monocrotaline-induced heart failure

Neurohormonal activation has been shown to be a major factor in congestive heart failure progression and mortality. The beneficial effects obtained in clinical trials with angiotensin converting enzyme (ACE) inhibitors, beta-blockers and aldosterone antagonists have confirmed this hypothesis. 5,6-Diisobutirroyloxy-2-methyl-aminotetraline hydrochloride (nolomirole) is a selective agonist of prejunctional D(2)-dopaminergic and alpha(2)-adrenergic receptors. The stimulation of these receptors inhibits catecholamine release from sympathetic nerve endings. To confirm that this mechanism can be useful in congestive heart failure, we studied the effects of nolomirole on monocrotaline-induced congestive heart failure. The ACE inhibitor trandolapril was used as reference compound. Rats were given single intraperitoneal injection of either saline (control group; n=20) or monocrotaline (50 mg kg(-1)). Three days later, the monocrotaline-treated animals were randomly allocated (n=50 per group) to oral treatment with distilled water (vehicle group), nolomirole (0.25 mg kg(-1)) twice a day, or trandolapril (0.3 mg kg(-1)) once a day up to sacrifice. On the fourth week after monocrotaline injection, animals with signs of congestive heart failure were sacrificed for evaluation of heart hypertrophy and neuroendocrine alterations. Atrial natriuretic peptide (ANP) and alderosterone were determined by radioimmunoassay in plasma. Tissue norepinephrine concentration was quantified by high-pressure liquid chromatography. Nolomirole and trandolapril significantly reduced (a) hypertrophy of right atria and ventricles, (b) plasma levels of ANP and presence of pleural/peritoneal effusions and (c) norepinephrine depletion of right ventricle. These findings confirmed that nolomirole, like trandolapril, is able to attenuate the heart failure signs in the monocrotaline-induced congestive heart failure model.

Two cases of familial primary pulmonary hypertension

Case 1, a 28-year-old woman (third daughter of Case 2) delivered her first child in September 2000, but leg edema and dyspnea on exertion appeared the following January. At the time of our first examination of the patient in May 2001, a chest X-ray showed cardiomegaly and pulmonary artery enlargement. Echocardiography demonstrated enlargement of the right ventricle and small left ventricular dimensions, and an electrocardiogram revealed right ventricle hypertrophy. After perfusion-ventilation lung scintigraphy and cardiac catheterization, she was diagnosed as having primary pulmonary hypertension (PPH). Although she was discharged with prescriptions for a diuretic, warfarin and beraprost sodium, she died of a pulmonary hypertensive crisis twenty days after readmission. Case 2, a 60-year-old woman(mother of Case 1) developed the same symptoms as those in Case 1, in May 2001, but recovered after medication. PPH is a rare disease and only a few familial cases are reported. In this family, the eldest daughter of Case 2 had also died of pulmonary hypertension ten years ago, several months after her first delivery. In contrast to the daughters, the mother's symptoms developed gradually.

Right Ventricular Enlargement on Chest Computed Tomography

Background— In patients with acute pulmonary embolism (PE), rapid and accurate risk assessment is paramount in selecting the appropriate treatment strategy. Right ventricular (RV) enlargement on chest CT has previously been shown to correlate with an unstable hospital course, but its role as a predictor of death is unknown.

Methods and Results— We evaluated 431 consecutive patients (mean age, 59±16 years; 55% women) with acute PE confirmed by multidetector-row chest CT. With the use of multiplanar reformats of axial CT data, CT 4-chamber (4-CH) views were reconstructed and right and left ventricular dimensions (RV D , LV D ) were measured. RV enlargement, defined as RV D /LV D >0.9, was present in 276 (64.0%; 95% CI, 59.5% to 68.6%) patients. Thirty-day mortality rate was 15.6% (95% CI, 11.3% to 19.9%) in patients with and 7.7% (95% CI, 3.5% to 12.0%) without RV enlargement (log rank, P =0.018). The hazard ratio of RV D /LV D >0.9 for predicting 30-day death was 3.36 (95% CI, 1.13 to 9.97; P =0.029). On multivariable analysis, RV enlargement predicted 30-day death (hazard ratio, 5.17; 95% CI, 1.63 to 16.35; P =0.005) after adjusting for pneumonia (hazard ratio, 2.95; 95% CI, 1.19 to 3.83; P =0.002), cancer (hazard ratio, 2.13; 95% CI, 1.19 to 3.83; P =0.011), chronic lung disease (hazard ratio, 2.00; 95% CI, 1.04 to 3.86; P =0.039), and age (hazard ratio, 1.03; 95% CI, 1.01 to 1.05; P =0.005).

Conclusions— In patients with acute PE, RV enlargement on reconstructed CT 4-CH view helps predict early death.

Pulmonary Hypertension and Right Heart Failure in Pituitary Adenylate Cyclase–Activating Polypeptide Type I Receptor–Deficient Mice

Background— Pituitary adenylate cyclase–activating polypeptide (PACAP), acting via 3 different G protein–coupled receptors, has been implicated in the regulation of several homeostatic systems in the body, including cardiopulmonary control. To define the physiologic role of the PACAP-preferring type I receptor, PAC1, in cardiopulmonary function, we developed a mutant mouse strain lacking functional PAC1 receptors.

Methods and Results— When PAC1-deficient mice were crossed onto a C57BL/6 background, almost all mutants died during the second postnatal week. Whereas mutant mice were indistinguishable from their wild-type littermates at birth, they showed progressive weakness and died from rapidly developing heart failure. Right ventricles of PAC1 mutants were massively dilated and showed cardiac myocyte hypertrophy, whereas left ventricular structure was unaltered. On direct cardiac catheterization, right ventricular pressure was elevated by 45% in PAC1-deficient mice, indicating increased pulmonary artery pressure, as no malformations were detected in the valves or outflow tract of the right ventricle. Consistent with elevated pulmonary pressure, lung capillary density was decreased by 30% and small pulmonary arteries of mutant mice had significant vascular smooth muscle cell hypertrophy compared with wild-type mice.

Conclusions— Whereas PACAP induces vasodilation in isolated pulmonary vessels in wild-type mice, the absence of its specific receptor PAC1 causes pulmonary hypertension and right heart failure after birth. These in vivo findings demonstrate the crucial importance of PAC1-mediated signaling for the maintenance of normal pulmonary vascular tone during early postnatal life.

GREATER HYPERTROPHY IN RIGHT THAN LEFT VENTRICLES IS ASSOCIATED WITH PULMONARY VASCULOPATHY IN SINOAORTIC-DENERVATED WISTAR-KYOTO RATS

1. Biventricular hypertrophy has been described in a high blood pressure variability (BPV) model of sinoaortic-denervated (SAD) rats without systemic hypertension. To explore the possible involvement of the lung in SAD-induced right ventricular hypertrophy (RVH), we examined lung morphology, in addition to systemic haemodynamics and ventricle morphology, in Wistar-Kyoto rats 32 weeks after SAD. 2. In Wistar-Kyoto rats 32 weeks after SAD, there existed a substantial elevation in BPV, with no change in the average level of arterial pressure. Biventricular hypertrophy following SAD was characterized by a greater hypertrophy in right than left ventricles; both absolute and normalized right ventricular weights were significantly increased by 22 and 27%, respectively, and only normalized left ventricular weight was significantly increased by 12%. No infarcts were found in any ventricles examined. 3. In the lung, the most prominent change following SAD was pulmonary vasculopathy, including wall thickening, perivascular fibrosis and cell infiltration. In pulmonary arteries with an internal diameter of 70-130 microm, the external diameter, wall thickness and wall thickness to internal diameter ratio were increased in SAD compared with control rats. 4. There was no correlation between right and left ventricular weights. In contrast with BPV-correlated left ventricular weight, right ventricular weight was correlated with the wall thickness of the pulmonary artery, but not with BPV. 5. These findings suggest that greater RVH following SAD is associated with pulmonary vasculopathy, but is not secondary to the left ventricular problems or high BPV.

Effects of epoprostenol on right ventricular hypertrophy and dilatation in pulmonary hypertension

OBJECTIVES

To gain more knowledge of changes in main pulmonary artery flow and right ventricular mass and volumes in patients with pulmonary hypertension during epoprostenol therapy.

METHODS

Eleven patients (9 women) were evaluated before the start of therapy and every 4 months thereafter. Right and left ventricular volumes and masses were measured by cine MRI. Flow was measured with MRI velocity quantification. At the same times, 6-min walking tests were performed. Right-heart catheterizations were performed at baseline and after 1 year.

RESULTS

Right ventricular mass in the patient group was significantly higher from that in a control group of healthy volunteers (95 +/- 26 g vs 42 +/- 10 g, p < 0.05 [mean +/- SD]), whereas the stroke volume was lower (34 +/- 11 mL vs 81 +/- 11 mL, p < 0.05). The greatest improvement in right ventricular stroke volume (to 41 +/- 11 mL, p < 0.05) took place in the first 4 months. During the 1-year follow-up, right ventricular end-diastolic volume and mass did not change, and mean pulmonary artery pressure remained nearly stable at 55 mm Hg at baseline and 53 mm Hg after 1 year. Pulmonary vascular resistance decreased by 12.5% (p = 0.06).

CONCLUSIONS

From these data we conclude that epoprostenol lowers pulmonary vascular resistance, leading to an increase in pulmonary artery flow. This increase in pulmonary artery flow corresponds well with the increase in 6-min walking distance and can be noninvasively monitored by MRI (flow quantification). Right ventricular dilatation and hypertrophy are not reversed by epoprostenol therapy, but do not progress either.

[Right ventricular involvement in hypertrophic cardiomyopathy. A case report and brief review of the literature]

A clinical case of non-obstructive hypertrophic cardiomyopathy with involvement of the right ventricle is reported. The patient was a 42-year-old male with symptoms suggesting an effort angina of recent onset. The diagnosis was established by echocardiography, which showed asymmetric hypertrophy of the interventricular septum (20 mm), hypertrophy of the right ventricular free wall, and severe hypertrophy of the septal papillary muscle of the tricuspid valve. The patient underwent a complete diagnostic evaluation, including exercise stress test, Holter monitoring, magnetic resonance, myocardial tomoscintigraphy and complete hemodynamic assessment. Medical treatment with atenolol 50 mg day was started; at 1-year follow-up the patient's clinical conditions are good, with decrease of anginal episodes. The literature review elicits the paucity of information about this condition, despite a frequent involvement of both ventricles in hypertrophic obstructive cardiomyopathy. The case reported shows two atypical aspects: a) the involvement of the right ventricle in non-obstructive hypertrophic cardiomyopathy is anecdotal; b) this pattern of hypertrophy (right ventricular free wall/septal papillary muscle) has never been previously reported. Right ventricular involvement in patients with hypertrophic cardiomyopathy must be carefully investigated, because it may be more frequent than conventionally deemed.

[Pulmonary hypertension right and left cardiac cavities in patients with systemic scleroderma]

Lung lesion is a most common organ changes in systemic scleroderma (SSD) detectable in approximately 70% of the patients at autopsy. Echocardiography is now one of the main non-invasive diagnostic methods for pulmonary hypertension (PH), in patients with scleroderma in particular. The study was undertaken to examine the incidence of PH and the specific features of its development in patients with SSD. Thirty-one patients with SSD (30 females and 1 males) treated at the rheumatological unit of the regional clinical hospital in 2000 to 2002 were examined. The patients' age ranged from 33 to 75 years (mean 47.7 +/- 1.7 years). Pulmonary systolic blood pressure (PSBP) (higher than 30 mm Hg) was recorded in 51.6% of the patients. Hypertrophy of the right ventricle (RV) (more than 0.5-cm increases in the thickness of its anterior wall) was found in 20 (64.5%) patients with SSD, 4 cases had hypertrophy of the RV anterior wall without resting elevated PSBP. More than 2.5-cm RV dilation was observed in 6 (19.4%) patients. This study has provided evidence for that echocardiography is of high informative value in detecting PH and right cardiac changes in patients with systemic scleroderma, which shows this technique to be a screening in these cases.

The superoxide dismutase mimetic, tempol, blunts right ventricular hypertrophy in chronic hypoxic rats

1. The purpose of this study was to investigate whether a membrane-permeable superoxide dismutase mimetic, tempol, added either alone or in combination with the nitric oxide (NO) donor molsidomine, prevents the development of pulmonary hypertension (PH) in chronic hypoxic rats. 2. Chronic hypobaric hypoxia (10% oxygen) for 2 weeks increased the right ventricular systolic pressure (RVSP), right ventricle and lung wet weight. Relaxations evoked by acetylcholine (ACh) and the molsidomine metabolite SIN-1 were impaired in isolated proximal, but not distal pulmonary arteries, from chronic hypoxic rats. 3. Treatment with tempol (86 mg x kg(-1) day(-1) in drinking water) normalized RVSP and reduced right ventricular hypertrophy, while systemic blood pressure, lung and liver weights, and blunted ACh relaxation of pulmonary arteries were unchanged. 4. Treatment with molsidomine (15 mg x kg(-1) day(-1) in drinking water) had the same effects as tempol, except that liver weight was reduced, and potassium and U46619-evoked vasoconstrictions in pulmonary arteries were increased. Combining tempol and molsidomine did not have additional effects compared to tempol alone. ACh relaxation in pulmonary arteries was not normalized by these treatments. 5. The media to lumen diameter ratio of the pulmonary arteries was greater for the hypoxic rats compared to the normoxic rats, and was not reversed by treatment with tempol, molsidomine, or the combination of tempol and molsidomine. 6. We conclude that tempol, like molsidomine, is able to correct RVSP and reduce right ventricular weight in the rat hypoxic model. Functional and structural properties of pulmonary small arteries were little affected. The results support the possibility that superoxide dismutase mimetics may be a useful means for the treatment of PH.

[Electrocardiographic picture in patients with congenital defect of atrial septum operated upon in adult age]

Electrocardiograms from 30 patients with congenital atrial septal defect operated upon in adult age were analyzed. One of frequent variants of QRS configuration in standard leads was SIqIII type. It was observed in 50% of patients. Most frequent (in 67% of patients) variants of QRS configuration in lead V1 were rSr' and rSR'. Signs of right ventricular hypertrophy were most often found in a group of patients with high pulmonary hypertension. Changes of terminal portion of ventricular complex such as negative or biphasic T waves were found in 29 of 30 patients (in 63% of cases these changes were localized in leads V1-V3).

Decreased plasma neurohormones and improved cardiac performance after surgical treatment of chronic pulmonary embolism

The findings of this case report suggest that quantitative assessment of plasma neurohormones and magnetic resonance imaging functional parameters in patients with right ventricular pressure overload due to chronic pulmonary embolism might be used as indicators for right ventricular function before and after intervention. Monitoring of changes in these parameters may provide quantitative follow-up of right ventricular function in these patients.

Double-chambered right ventricle or sub-infundibular stenosis assessed by cardiovascular magnetic resonance

This paper presents magnetic resonance findings in four adults with double-chambered right ventricle or sub-infundibular stenosis, a condition that is treatable by surgery, but which can be difficult to assess echocardiographically. Four patients referred for cardiovascular magnetic resonance in the last 2 years were identified from CMR findings, although not necessarily from previous echocardiography, as having sub-infundibular stenosis. We used multislice spin echo imaging, cine imaging in oblique sagittal planes, and phase velocity mapping. We performed spin echo imaging of a post-mortem heart without known structural abnormality to illustrate right ventricular myocardial morphology. Results in patients showed evidence of sub-infundibular muscular obstruction separating the hypertrophied inlet and apical portions of the right ventricle from a thin-walled, unobstructed infundibular region in each case, with a systolic jet originating at least 15 mm beneath the unstenosed pulmonary valve. In addition to previously described structural components contributing to stenosis--enlargement and/or displacement of the septomarginal trabeculation, septoparietal trabeculations or the moderator band--CMR suggested additional components: a right ventricular papillary muscle in one, an anteriorly bulging aortic sinus in one, and hypertrophied muscular ridges of the parietal wall of the right ventricle. Even in this small group of patients, the causes of sub-infundibular stenosis appeared to be varied and multi-factorial. The abilities of magnetic resonance to give unrestricted, multi-planar views of right ventricular anatomy, movement and flow make it well suited for diagnosis and characterization of sub-infundibular stenosis, especially in adults.

Ventricular hypertrophy plus neurohumoral activation is necessary to alter the cardiac beta-adrenoceptor system in experimental heart failure

Treatment of rats with monocrotaline (MCT) leads to pulmonary hypertension, right ventricular (RV) hypertrophy, and finally to RV heart failure. This is associated with characteristic changes in right ventricular beta-adrenoceptors (beta-AR), neuronal noradrenaline transporter (NAT) density and activity (uptake1), and G protein-coupled receptor kinase (GRK) activity. This study aimed to find out factors that determine beta-AR, uptake1, and GRK changes. Thus, 6-week-old rats were treated with 50 mg/kg MCT subcutaneous or 0.9% saline. Within 13 to 19 days after MCT application (group A), RV weight (222+/-6 versus 147+/-5 mg) and RV/left ventricular (LV) weight ratio (0.42+/-0.01 versus 0.29+/-0.01) were significantly increased, whereas plasma noradrenaline, RV beta-AR density, RV NAT density and activity, and RV GRK activity were not significantly altered. Twenty-one to twenty-eight days after MCT (group B), however, not only RV weight (316+/-4 versus 148+/-2 mg) and RV/LV weight ratio (0.61+/-0.01 versus 0.3+/-0.01) were markedly increased but also plasma noradrenaline (645+/-63 versus 278+/-18 pg/mL); now, RV beta-AR density (13.4+/-1.3 versus 26.5+/-1.1 fmol/mg protein), RV NAT density (50.9+/-11.3 versus 79.6+/-2.9 fmol/mg protein), and RV NAT activity (65.4+/-7.4 versus 111.8+/-15.9 pmol [3H]-NA/mg tissue slices/15 min) were significantly decreased and RV-membrane GRK activity (100+/-15 versus 67+/-6 [32P]-rhodopsin in cpm) significantly increased. LV parameters of MCT-treated rats were only marginally different from control LV. We conclude that in MCT-treated rats ventricular hypertrophy per se is not sufficient to cause characteristic alterations in the myocardial beta-AR system often seen in heart failure; only if ventricular hypertrophy is associated with neurohumoral activation beta-ARs are downregulated and GRK activity is increased.

Simvastatin attenuates smooth muscle neointimal proliferation and pulmonary hypertension in rats

Hypertensive pulmonary vascular disease is characterized by abnormal proliferation of vascular endothelial and smooth muscle cells, leading to occlusion of pulmonary arterioles, pulmonary hypertension, right ventricular failure, and death. Compounds with antiproliferative effects on vascular endothelial and smooth muscle cells, such as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, may prevent the development of experimental hypertensive pulmonary vascular disease. Pneumonectomized rats injected with monocrotaline at 7 days develop severe hypertensive pulmonary vascular disease with neointimal formation. Rats were randomized to receive either vehicle or treatment with the HMG-CoA reductase inhibitor simvastatin (2 mg/kg per day). By Day 35, rats that received vehicle had higher mean pulmonary arterial pressures (53 +/- 2 mm Hg) and right ventricular hypertrophy (right ventricle/[left ventricle plus septum] [RV/LV+S] = 0.78 +/- 0.09) than rats in Group PMS5-35 that received simvastatin from Day 5 to 35 (mean pulmonary arterial pressure = 27 +/- 3 mm Hg, RV/LV+S = 0.34 +/- 0.08; p < or = 0.001). Pulmonary vascular remodeling with neointimal formation consisting of vascular smooth muscle cells was more severe in vehicle-treated rats (vascular occlusion score, 1.98 +/- 0.02) than in Group PMS5-35 (vascular occlusion score, 0.59 +/- 0.46; p < 0.001). In addition, lung endothelial nitric oxide synthase gene expression was decreased in vehicle-treated animals but was restored toward normal levels in simvastatin-treated animals. Simvastatin attenuates monocrotaline-induced pulmonary vascular remodeling with neointimal formation, pulmonary arterial hypertension, and right ventricular hypertrophy in rats.

[Electrocardiographic signs of right ventricular overload useful in improving diagnosis of chronic thromboembolic pulmonary hypertension (CTE-PH) in patients with chronic exertional dyspnea]

The early recognition of chronic thromboembolic pulmonary hypertension (CTE-PH) is troublesome because of "honey moon" period with chronic dyspnea on exertion as the only one symptom. To find if routine electrocardiography may be useful in improving the diagnosis, value of right ventricular overload (RVO) signs in recognition echocardiographically determined chronic pulmonary hypertension (CPH) and angiographically confirmed CTE-PH in 90 consecutive patients hospitalized due to chronic exertional dyspnea was studied. CPE was found in 76.5% and CTE-PH in 33% of those patients, at least one of twelve founded electrocardiographic signs of RVO was present in 50% patients. The most frequently occurred signs: negative T wave in lead V1-V6, right axis deviation and pulmonale P wave as well as 9 other occurred at frequency below 20% signs of RVO had low to medium sensitivity and negative predictive value and 80-90% positive predictive value for diagnosing CPE and 90-100% positive predictive value for diagnosing CTE-PH. It was concluded that in patients with chronic exertional dyspnea electrocardiographic signs of RVO may be useful in initial diagnosing of CPH and CTE-PH in particular.