Non-Uniform Bioaccumulation of Lead and Arsenic in Two Remote Regions of the Human Heart's Left Ventricle: A Post-Mortem Study.

The extent of heavy-metal-induced cardiotoxicity is proportional to the levels of metal bioaccumulation, and it was previously assumed that heavy metals accumulate uniformly in the myocardium. Therefore, the aim of this study was to investigate concentrations of metals and metalloids in two distant regions of the left ventricle (LV), the base of the LV, and apex of the LV using inductively coupled plasma mass spectrometry (ICP-MS). We also examined the potential correlation between metal levels and the thickness of the interventricular septum in twenty LV specimens (ten from the base of LV and ten from the apex of LV) from 10 individuals (mean age 75 ± 6 years). We found significantly higher concentrations of arsenic and lead in the LV apex compared to the base of the LV. We also found a positive correlation between the concentrations of arsenic in the myocardium of LV and the thickness of the interventricular septum. Our results indicate that arsenic and lead accumulate to a higher extent in the apex of the LV compared to the base of the LV. Therefore, future studies designed to measure levels of metals in heart muscle should consider non-uniform accumulation of metals in the myocardium.

Cardiovascular magnetic resonance imaging derived septal curvature in neonates with bronchopulmonary dysplasia associated pulmonary hypertension.

BACKGROUND: Bronchopulmonary dysplasia (BPD) associated with pulmonary hypertension (PH) is a significant source of morbidity and mortality in premature infants. Recent advances have allowed the use of cardiovascular magnetic resonance (CMR) in the assessment of respiratory and cardiac disease in infants with BPD. In adults and older pediatric patients, decreased CMR interventricular septal curvature correlates with increased mean pulmonary artery pressure and pulmonary vascular resistance. The current study sought to determine the relationship of CMR derived septal curvature in neonates with BPD and BPD-PH with a need for PH therapy. METHODS: Forty moderate or severe BPD and 12 mild BPD or control infants were imaged without contrast between 38 and 47 weeks post-menstrual age on a neonatal-sized, neonatal intensive care unit-sited 1.5 T CMR scanner. CMR indices including eccentricity index (CMR-EI) and septal curvature were measured and compared to BPD severity and clinical outcomes including hospital length of stay (LOS), duration of respiratory support, respiratory support level at discharge and PH therapy. RESULTS: CMR-EI was directly associated and septal curvature was inversely associated with BPD severity. In a univariate analysis, CMR-EI and septal curvature were associated with increased hospital LOS, duration of respiratory support, respiratory support at hospital discharge, and need for PH therapy. In multivariable analysis CMR-EI was associated with hospital LOS and duration of respiratory support and septal curvature was associated with respiratory support at hospital discharge. Septal curvature was the only clinical or CMR variable associated with need for PH therapy (R2 = 0.66, p = 0.0014) in multivariable analysis demonstrating improved discrimination beyond CMR-EI. CONCLUSIONS: CMR derived septal curvature correlates significantly with clinical outcomes including hospital LOS, duration of respiratory support, respiratory support level at hospital discharge, and PH therapy in neonates with BPD and BPD-PH. Further, CMR derived septal curvature demonstrated improved discrimination of need for PH therapy and respiratory support at discharge compared to clinical variables and other CMR indices, supporting septal curvature as a non-invasive marker of PH in this population with potential to guide management strategies.

Effect of Natural Cytokine Complex on the Structure and Metabolism of the Cardiac Conduction System in the Myocardium under Normally and Increased Hemodynamic Load.

Effect of natural complex of cytokines with activity of IL-1, IL-2, IL-6, TNF, MIF, and GTFß on the structure and metabolism of conduction cardiomyocytes was assessed in the control and under acute experimental aortic stenosis. After systemic administration of the cytokine complex in the control, structural abnormalities were revealed in a relatively low number of conduction cardiomyocytes; their relative number increased in the left ventricle and interventricular septum. When the complex was administered against the background of aortic stenosis, morphological changes in the conduction system were seen in a significant number of cells with their plasma imbibition, especially in the left ventricle and interventricular septum. Systemic administration of the natural cytokine complex inhibited the major metabolic processes in the conduction system, both in the control and under conditions of sharply increased hemodynamic load. In conduction cardiomyocytes, deceleration of glycolysis and citric acid cycle, inhibition of oxidation of free fatty acids and their metabolites, and suppression of shuttle mechanisms and biosynthetic reactions were observed. Increased blood levels of cytokines, primarily of the proinflammatory ones, can cause structural and metabolic disturbances in the cardiac conduction system and promote the development of arrhythmias, especially in case of sharply increased hemodynamic load.

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

OBJECTIVE: To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. METHODS: The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. RESULTS: There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. CONCLUSIONS: Ethanol vapour exposure may lead to ventricular septal defect.

Heterogeneity of myocardial iron distribution in response to chelation therapy in patients with transfusion-dependent anemias.

The purpose of this study is to examine the effect of different iron chelation regimens on the distribution of myocardial iron in patients with transfusion-dependent anemias. Institutional review board approval was obtained. Patients treated with iron chelation therapy who had undergone baseline and 1-year follow-up cardiac T2* MR studies in a four-year period were identified retrospectively. One hundred and eight patients (44 % male, mean age 31.6 ± 9.7 years) were included. The interventricular septum on three short-axis slices (basal, mid and apical) was divided into anterior and inferior regions of interest for T2* analysis. Cardiac iron concentration (CIC) was calculated from T2* values. Statistical analysis included analysis of variance and paired t-test, using Bonferroni adjustment in all pairwise comparisons. At baseline, T2* measurements varied significantly across all six regions (p < 0.001): lowest in the mid anteroseptum (mean 22.3 ± 10.1 ms) and highest in the apical inferoseptum (mean 26.2 ± 12.8 ms). At follow-up, T2* and CIC values improved significantly in all segments [mean change of 3.78 ms (95 % CI (2.93, 4.62), p < 0.001) and 0.23 mg/g (95 % CI (0.16, 0.29), p < 0.001), respectively]. Change in T2* values varied significantly between segments (p < 0.001) with greatest improvement in the apical inferoseptum [4.26 ms, 95 % CI (2.42, 6.11)] and least improvement in the basal anteroseptum [2.95 ms, 95 % CI (1.37, 4.54)]. The largest improvement in T2* values was noted in patients treated with deferiprone [4.96 ms, 95 % CI (2.34, 7.58)]. There was a statistically significant difference in improvement in CIC values between chelation regimens (p = 0.016). This is the first study to report heterogeneity in response to iron chelating drugs with variable segmental changes in T2* values.

Characteristics of systolic and diastolic potentials recorded in the left interventricular septum in verapamil-sensitive left ventricular tachycardia.

We studied the electrophysiological characteristics of systolic (SP) and diastolic (DP) potentials recorded during sinus rhythm (SR) in the left interventricular septum of a 27 year-old woman presenting with verapamil-sensitive idiopathic left ventricular tachycardia (VT). During SR, and during VT, SP was activated from ventricular base-to-apex, and DP from apex-to-base. SP and DP were both detected at the site of successful ablation during SR, whereas during VT, DP was detected away from the earliest activation site. Thus, SP apparently reflected a critical component of the reentrant circuit, while DP reflected the activation of a bystander pathway.

Overexpression of coupling factor 6 attenuates exercise-induced physiological cardiac hypertrophy by inhibiting PI3K/Akt signaling in mice.

BACKGROUND: Regular exercise improves systolic cardiac dysfunction through Akt cascade-mediated physiological hypertrophy in congestive heart failure. Tissue acidosis impairs Akt cascade, and coupling factor 6 induces tissue acidosis via activation of ecto-F(1)F(o) complex. We tested the hypothesis that coupling factor 6 attenuates physiological cardiac hypertrophy induced by exercise and its benefit in mice. METHODS AND RESULTS: Adult wild-type mice (n = 20) and coupling factor 6-overexpressing transgenic mice (n = 20) were divided into two groups with or without 4-week exercise consisting of 90-min swimming twice daily. Left ventricular posterior wall and interventricular septum thicknesses were increased by 0.12 ±â€Š0.1 and 0.16 ±â€Š0.1 mm, respectively, after 4-week swimming in wild-type mice (both P < 0.01), but unchanged in transgenic mice. Fractional shortening was increased from 37 ±â€Š1 to 41 ±â€Š1% after 4-week swimming in wild-type mice (P < 0.05), whereas it was unchanged in transgenic. The insulin-like growth factor 1 (IGF-1) receptor protein and its phosphorylated form in the heart were both increased by 1.83 ±â€Š0.23 and 1.83 ±â€Š0.09 times, respectively, after 4-week swimming in wild-type mice (both P < 0.05), but were unchanged in transgenic. Downstream phosphoinsulin receptor substrate 1, phosphoinositide 3-kinase, and phospho-Akt were increased by 2.22 ±â€Š0.22, 1.78 ±â€Š0.31, and 2.24 ±â€Š0.49 times, respectively, in wild-type mice (all P < 0.05), but were unchanged in transgenic. Restoration of phospho-Akt by IGF-1 injection recovered left ventricular hypertrophy and systolic function after 4-week swimming in transgenic. CONCLUSION: Overexpression of coupling factor 6 attenuates exercise-induced physiological cardiac hypertrophy by downregulating Akt signaling, thereby cancelling its benefit for cardiac function in mice. Reduction in coupling factor 6 level seems to be useful for drawing the exercising effects on cardiac function.

A novel anti-fibrotic agent, baicalein, for the treatment of myocardial fibrosis in spontaneously hypertensive rats.

Myocardial interstitial fibrosis causes left ventricular stiffness and diastolic dysfunction. Despite its clinical significance, treatment options are limited. The flavonoid baicalein, extracted from roots of a Chinese medicinal plant, Scutellaria baicalensis Georgi was shown to inhibit liver fibrosis. This study sought to investigate whether chronic treatment with baicalein could attenuate myocardial fibrosis in spontaneously hypertensive rats (SHR). SHR were treated daily with baicalein while the control group received vehicle. At the end of study, SHR control group developed significant myocardial fibrosis that was attenuated by baicalein treatment for 4 and 12 weeks. Rats treated with baicalein were protected against an increase in heart to body weight ratio, plasma level of brain natriuretic peptides, intraventricular septum thickness, myocardial collagen volume of left ventricle (all P<0.05, respectively). The antifibrotic effects of baicalein were further illustrated by the suppressed expression of left ventricle pro-collagens I and III accompanied by the decreased expression of 12-lipoxygenase, and by reduced expression and activity of matrix metallopeptidase 9 and extracellular signal-regulated kinases. The present results show for the first time that baicalein can inhibit cardiac fibrosis in hypertensive rats.

Alcohol septal ablation to overcome shock.

A 69-year-old man, known with hypertrophic obstructive cardiomyopathy (HOCM), was referred to our hospital because of progressive hypoxaemia and sepsis after admission for respiratory infection. Once at the emergency department, cardiopulmonary resuscitation, intubation and mechanical ventilation were necessary. Despite vasopressors and colloids the patient remained haemodynamically unstable. Because of the conviction that the distributive shock, caused by sepsis, was worsened by an associated obstructive shock related to the HOCM, an alcohol septal ablation (ASA) was attempted in these acute circumstances. Immediately after the ASA the gradient over the left ventricular outflow tract disappeared and the mean arterial pressure and oxygenation increased. Despite his cardiovascular recuperation the patient died a couple of days later. Nevertheless we achieved an improvement of the haemodynamic situation of this patient with HOCM by performing an urgent ASA.

Successful alcohol septal ablation for late recurrence of left ventricular outflow tract obstruction after surgical myectomy in hypertrophic obstructive cardiomyopathy.

An 18-year-old male patient, known with familial hypertrophic obstructive cardiomyopathy underwent a septal myectomy 10 years ago for significant left ventricular outflow tract (LVOT) obstruction. During follow-up a progressive increase in LVOT gradient was noted in association with severe mitral valve regurgitation. The patient underwent percutaneous alcohol septal ablation to induce regression of left ventricular hypertrophy. Coronary angiography, with intracoronary contrast and guided by echocardiographic imaging, was applied for localisation of the appropriate septal branch. The vessel was subsequently injected with 1.5 cc ethanol. No procedure-related complications were reported. The LVOT gradient decreased from 90 mmHg to 48 and 45 mmHg at rest 6 weeks and 6 months, respectively, after the procedure. Mitral valve regurgitation was significantly reduced. This case nicely illustrates the feasibility of percutaneous alcohol septal ablation for recurrent LVOT obstruction 10 years after myectomy.

Early epirubicin-induced myocardial dysfunction revealed by serial tissue Doppler echocardiography: correlation with inflammatory and oxidative stress markers.

A phase II, open, nonrandomized trial was carried out in a group of epirubicin-treated patients with cancer at different sites with the aim of detecting early preclinical changes that are predictive of the risk for heart failure. All patients underwent conventional echocardiography, as well as tissue Doppler imaging (TDI) with strain (sigma) and strain rate (SR), a very accurate technique for detecting minimal changes in cardiac left ventricular (LV) function. Moreover, echocardiographic changes identified during epirubicin treatment were compared with those of a series of biochemical markers of both myocardial damage and inflammation/oxidative stress. Sixteen patients (male-to-female ratio, 3:13; mean age +/- standard deviation, 56 +/-3 years; range, 27-75 years) with histologically confirmed tumors at different sites, scheduled to be treated with an epirubicin-based chemotherapy regimen, were enrolled in the study. A significant impairment in systolic LV function was observed after 200 mg/m2 of epirubicin; this was shown by a lower SR peak compared with baseline (1.82 +/- 0.57/second versus 1.45 +/- 0.44/second), whereas sigma remained unchanged. The following significant changes in LV diastolic function occurred only after 300 mg/m2 of epirubicin: a decrease in conventional early/late diastolic (E/A) velocities (1.16 +/- 0.31 versus 0.93 +/- 0.24) and a reduction in both the E(m) wave in the basal portion of the interventricular septum (8.86 +/- 1.73 cm/second versus 7.51 +/- 2.30 cm/second) and in the E(m)/A(m) ratio (1.09 +/- 0.51 versus 0.83 +/- 0.51), as measured using the TDI technique. No significant changes in LV ejection fraction were observed. Baseline values of brain natriuretic peptide, troponin I, myoglobin, and creatine kinase-myocardial subfraction were within the normal range and no significant changes were observed throughout the study. Levels of interleukin (IL)-6 and its soluble receptor (sIL-6R) and reactive oxygen species increased significantly, whereas glutathione peroxidase (GPx) levels decreased significantly, after 200 mg/m2 of epirubicin. Significant correlations between the reduction in the SR peak (deltaSR) after 200 mg/m2 of epirubicin and the increase in IL-6 and ROS and decrease in GPx were observed. The multiple regression analysis showed that the only independent predictive variable for deltaSR was ROS level. Our data show that: (a) subtle cardiac abnormalities may occur at epirubicin doses significantly below those known to be potentially clinically harmful and (b) the earliest myocardial impairment affects LV systolic rather than diastolic function. Early contractility impairment during epirubicin treatment was associated with high levels of ROS and markers of inflammation. The clinical meaningfulness of our findings warrants further investigations in a larger number of patients for a longer period of follow-up.