Assessment of fetal left ventricular modified myocardial performance index and its prognostic significance for adverse perinatal outcome in intrahepatic cholestasis of pregnancy.

Objective: To investigate the association between fetal left ventricular modified myocardial performance index (LMPI) and intrahepatic cholestasis of pregnancy (ICP) and to evaluate the value of LMPI in predicting adverse perinatal outcomes in ICP.Study design: In a cross-sectional case-control study, 40 women with ICP were compared with 40 gestational age-matched healthy controls. The isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and ejection time (ET) were measured using the Doppler signals of the opening and closing of the mitral and aortic valves. LMPI was calculated as (ICT + IRT)/ET. An adverse perinatal outcome was defined with at least one of the following: non-reassuring fetal heart rate tracing, umbilical cord pH <7.20, the presence of meconium in amnion, and neonatal intensive care unit (NICU) admission.Results: Mean gestational age at delivery and mean birth weight were significantly lower and the incidences of cesarean section rate, non-reassuring fetal heart rate tracing, the presence of meconium in amnion, and NICU admission were significantly higher in the ICP group (p < .01). Mean LMPI, ICT, and IRT values were significantly higher in the ICP group (p < .01). The area under the receiver operating characteristic (ROC) curve for LMPI in prediction of adverse perinatal outcome was 0.740 (95% CI: 0.607-0.873, p = .001) and a cut-off LMPI of 0.41 conferred a sensitivity of 85% and a specificity of 61%.Conclusions: There is an impaired global ventricular function in ICP fetuses demonstrated by increased LMPI. High LMPI is associated with adverse perinatal outcome in ICP.

Evaluation of Fetal Left Ventricular Size and Function Using Speckle-Tracking and the Simpson Rule.

OBJECTIVES: This study was conducted to evaluate left ventricular (LV) size and function in healthy fetuses and to test a cohort of fetuses at risk for abnormal function using speckle-tracking software. METHODS: Two hundred control fetuses were examined between 20 and 40 weeks' gestation. With the use of offline speckle-tracking software, the end-diastolic and end-systolic volumes were measured and the following computed: stroke volume (SV), SV per kilogram, cardiac output (CO), CO per kilogram, and ejection fraction. These were regressed against 7 independent variables related to the size, weight, and age of the fetuses. Five fetuses with risk factors for LV dysfunction were examined to sample the validity of the data from the control group. RESULTS: The R2 values for measurements of the end-diastolic volume, SV, and CO correlated with the 7 independent variables of fetal size and age (0.7-0.78), whereas the SV/kg, CO/kg, and ejection fraction had lower R2 values (0.02-0.1). The measurements were normally distributed (Shapiro-Wilke > 0.5). The 5 fetuses at risk for abnormal LV function had measurements of LV size and function that were consistent with the expected pathologic condition. CONCLUSIONS: Speckle tracking can provide a comprehensive evaluation of the size and function of the fetal LV.

Effect of Hypoxemia on Fetal Ventricular Deformation in a Chronically Instrumented Sheep Model.

We hypothesized that in near-term sheep fetuses, hypoxemia changes myocardial function as reflected in altered ventricular deformation on speckle-tracking echocardiography. Fetuses in 21 pregnant sheep were instrumented. After 4 d of recovery, fetal cardiac function was assessed by echocardiography at baseline, after 30 and 120 min of induced fetal hypoxemia and after its reversal. Left (LV) and right (RV) ventricular cardiac output and myocardial strain were measured. Baseline mean (standard deviation [SD]) LV and RV global longitudinal strains were -18.7% (3.8) and -14.3% (5.3). Baseline RV global longitudinal and circumferential deformations were less compared with those of the left ventricle (p = 0.016 and p < 0.005). LV, but not RV, global longitudinal strain was decreased (p = 0.003) compared with baseline with hypoxemia. Circumferential and radial strains did not exhibit significant changes. In the near-term sheep fetus, LV global longitudinal and circumferential strains are more negative than RV strains. Acute hypoxemia leads to LV rather than RV dysfunction as reflected by decreased deformation.

Study of Regional Left Ventricular Longitudinal Function in Fetuses with Gestational Diabetes Mellitus by Velocity Vector Imaging.

OBJECTIVE: The purpose of this study was to investigate the clinical value of velocity vector imaging in the assessment of regional left ventricular longitudinal function in fetuses with gestational diabetes mellitus. METHODS: Digital dynamic four-chamber views of 98 fetuses with gestational diabetes mellitus and 135 normal fetuses were collected and analyzed using velocity vector imaging. The regional tissue velocity, strain, and strain rate of the interventricular septum and left lateral wall were separately measured in systole and diastole. RESULTS: A total of 207 of 233 cases were analyzed successfully. Vs (systolic velocity) and Vd (diastolic velocity) were age-dependent and gradually decreased from the basal segment to the apical segment in the left ventricle (P < 0.05). The Vs after 32(+0) weeks, Vd after 28(+0) weeks, and S (strain), SRs (systolic strain rate), and SRd (diastolic strain rate) after 24(+0) weeks in the left ventricle of fetuses with GDM were obviously lower than the corresponding parameters of normal fetuses (P < 0.05). CONCLUSION: VVI can evaluate the fetal regional left ventricular longitudinal function.

Aorto-Left Ventricular Tunnel Successfully Repaired Immediately After Birth.

We describe the unusual case of a patient with an antenatal aorto-left ventricular tunnel (ALVT) diagnosis and severe left ventricular (LV) dysfunction who underwent successful repair immediately after birth. To the best of our knowledge, no such case has been reported in the English literature. Our case demonstrated that neonates at the worst end of the ALVT spectrum can survive and achieve normalization of LV function through a timely and multidisciplinary approach.

Effects of chronic hypoxia on cardiac function measured by pressure-volume catheter in fetal chickens.

Hypoxia is a common component of many developmental insults and has been studied in early-stage chicken development. However, its impact on cardiac function and arterial-ventricular coupling in late-stage chickens is relatively unknown. To test the hypothesis that hypoxic incubation would reduce baseline cardiac function but protect the heart during acute hypoxia in late-stage chickens, white Leghorn eggs were incubated at 21% O2 or 15% O2. At 90% of incubation (19 days), hypoxic incubation caused growth restriction (-20%) and increased the LV-to-body ratio (+41%). Left ventricular (LV) pressure-volume loops were measured in anesthetized chickens in normoxia and acute hypoxia (10% O2). Hypoxic incubation lowered the maximal rate of pressure generation (ΔP/ΔtMax; -22%) and output (-57%), whereas increasing end-systolic elastance (ELV; +31%) and arterial elastance (EA; +122%) at similar heart rates to normoxic incubation. Both hypoxic incubation and acute hypoxia lengthened the half-time of relaxation (τ; +24%). Acute hypoxia reduced heart rate (-8%) and increased end-diastolic pressure (+35%). Hearts were collected for mRNA analysis. Hypoxic incubation was marked by decreased mRNA expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase 2, Na(+)/Ca(2+) exchanger 1, phospholamban, and ryanodine receptor. In summary, hypoxic incubation reduces LV function in the late-stage chicken by slowing pressure generation and relaxation, which may be driven by altered intracellular excitation-contraction coupling. Cardiac efficiency is greatly reduced after hypoxic incubation. In both incubation groups acute hypoxia reduced diastolic function.

Tissue doppler myocardial velocity imaging in infants and children--a window into developmental changes of myocardial mechanics.

In adults, tissue Doppler myocardial velocity imaging (TDI) is a recommended component of routine echocardiography and particularly useful to assess diastolic function of the left ventricle. In contrast, color and pulsed-wave TDI velocities are less accepted in pediatrics, perhaps due to their strong age dependence in children. This review discusses the strengths and limitations of TDI velocity imaging in the pediatric age group. Myocardial velocities increase during normal childhood heart development, starting from fetal life, and these changes vary by cardiac segment. TDI velocity maturation opens an interesting window into the normal development of myocardial mechanics in childhood, but makes it difficult to interpret data in an individual child. Moreover, there is a wider range of normal for any given pediatric age than in adults. Still, TDI has been useful to monitor systolic heart function in children with cardiomyopathy or after heart transplantation. TDI studies revealed diastolic dysfunction in obese children and in cancer survivors with preclinical anthracycline cardiomyopathy. There is a growing body of studies using TDI to assess right heart function in children with congenital heart disease or pulmonary hypertension. Another potential strength of TDI velocities is the study of myocardial dyssynchrony where color TDI is well suited for rapid pediatric heart rates, even on fetal echocardiogram. Quantitative stress echocardiography with TDI is an emerging application in children that already offered insight into heart function in children with tetralogy of Fallot. Therefore, TDI velocity imaging should become part of the routine assessment of heart function in children.

Fetal sheep left ventricle is more sensitive than right ventricle to progressively worsening hypoxemia and acidemia.

OBJECTIVE: In a sheep model we tested the hypothesis that the fetal left ventricle is less tolerant to worsening acidemia than the right ventricle. STUDY DESIGN: At 106-124/145 days of gestation, 12 fetuses were instrumented. After a 4-day recovery, placental vascular resistance was increased by fetal angiotensin (AT) II infusion. After a 2h ATII infusion, to further deteriorate fetal oxygenation, maternal hypoxemia was induced. Fetal cardiac function and hemodynamics were assessed by tissue Doppler imaging (TDI) and pulsed Doppler imaging. Ultrasonography was performed at baseline, at 1 and 2h after the beginning of ATII infusion and during the ATII+hypoxemia phase. RESULTS: Fetal pH and pO2 decreased significantly and progressively during the experiment. Left ventricular TDI-derived isovolumic relaxation velocity (IVRV) was lower during ATII 2h and ATII+hypoxemia phases than at baseline. The IVRV deceleration was significantly less during the ATII+hypoxemia phase than at baseline. Right ventricular IVRV was significantly lower during the ATII+hypoxemia phase than at baseline. IVRV deceleration did not change. Only left ventricular IVRV deceleration correlated with fetal pO2 (R=0.36, p<0.05). Fetal right and left ventricular cardiac outputs, as well as umbilical artery, aortic isthmus and ductus venosus pulsatility indices remained unchanged during the experiment. CONCLUSION: Our results show that signs of cardiac dysfunction develop earlier in the left ventricle than in the right ventricle. The fetal left ventricle seems to be more sensitive to progressively worsening hypoxemia and acidemia than the right ventricle.

Speckle tracking-derived myocardial tissue deformation imaging in twin-twin transfusion syndrome: differences in strain and strain rate between donor and recipient twins.

OBJECTIVES: Twin-twin transfusion syndrome (TTTS) is a complex disorder with altered cardiovascular loading conditions that affects both donors and recipients. Myocardial tissue deformation analysis using vector velocity imaging is an angle-independent, speckle-tracking technique which can assess myocardial mechanics and may provide insight into cardiac dysfunction in TTTS. METHODS: Digital dynamic two-dimensional four-chamber views were interrogated offline. Images were acquired utilizing standard video frame rates (30 frames/s). The global longitudinal strain, systolic strain rate, and diastolic strain rate were measured in the left (LV) and right ventricles (RV) of 25 fetal pairs with TTTS and compared to 25 gestational age-matched normal controls. Pulsatility indices for the umbilical artery and middle cerebral artery were measured. RESULTS: The gestational age at evaluation was 20.5 ± 1.3 weeks. The donor LV systolic strain rate was higher, while the donor RV diastolic strain rate was significantly lower, than control values. The recipient longitudinal strain, systolic strain rate, and diastolic strain rate were significantly lower for both LV and RV in comparison to controls. The donor umbilical artery pulsatility index was higher than control values (1.92 ± 0.45 vs. 1.41 ± 0.25, p < 0.001), while the donor middle cerebral artery pulsatility index was lower (1.46 ± 0.28 vs. 1.87 ± 0.21). Recipient umbilical artery and middle cerebral artery pulsatility indices were no different than control values. CONCLUSIONS: In TTTS, both the donor and the recipient exhibit abnormalities of myocardial tissue deformation with ventricle-specific changes evident based on loading conditions. Donor LV systolic function is hyperdynamic due to hypovolemia and selective ejection into a low-resistance cerebrovascular circuit while the donor RV selectively ejects into a high-resistance placental circuit. Recipient RV and LV are both globally depressed with systolic and diastolic dysfunction. Further prospective validation of our findings using high frame rate analysis is indicated.

Prenatal diagnosis of polymorphic ventricular tachycardia using 64-channel magnetocardiography.

We describe polymorphic ventricular tachycardia (VT) diagnosed using fetal magnetocardiography (FMCG). The fetus of a 33-year-old Japanese female at 24 weeks of pregnancy was diagnosed as bradycardia (60 beats/min) by fetal cardiotocography (CTG). Ultrasound findings indicated a diagnosis of an atrioventricular (AV) block involving extrasystole, but FMCG revealed a polymorphic VT followed by ventricular asystole. Standard ECG immediately after cesarean section at 37 weeks of pregnancy confirmed long QT syndrome followed by nonsustained polymorphic VT and an advanced AV block with wide QRS. Echocardiography demonstrated moderate left ventricular dysfunction in the neonate requiring implantation with a permanent pacemaker.

Sinus bradycardia, Wolff Parkinson White, and left ventricular noncompaction: an embryologic connection?

Left ventricular noncompaction (LVNC) is an uncommon disorder that has recently been recognized as a distinct cardiomyopathy. LVNC is thought to result from an arrest in the normal process of myocardial compaction. The association of Wolff-Parkinson-White with noncompaction of the left ventricle is well recognized. Sinus bradycardia has also been associated with LVNC, although less frequently than that of Wolff-Parkinson-White. We report an infant with LVNC, Wolff-Parkinson-White, and progressive sinus bradycardia who had a myocardial vascular abnormality in the region of the sinus node evident on autopsy. We propose that the progressive nature of the conduction system abnormality was as a result of abnormal angiogenesis.

Revisiting animal models of aortic stenosis in the early gestation fetus.

BACKGROUND: Mechanisms leading to left ventricular hypoplasia and endocardial fibroelastosis in the fetus remain unknown. Prevailing theory is that obstruction to blood flow through the left ventricle leads to elevated end-diastolic pressures, compromised myocardial perfusion, and endocardial ischemia. Fetal interventions are now being performed, based on the presumption that they would prevent such pathogenic mechanisms. METHODS: Forty first-trimester fetal sheep (mean gestational age, 53 days) were studied. Severe fetal left ventricular outflow obstruction was created by banding the ascending aorta in 25 fetuses; 15 control fetuses underwent "sham" surgery with thoracotomy. Serial fetal echocardiography was used to assess left ventricular growth and fetal hemodynamics. Findings were correlated to morphologic and histopathologic changes, and intracardiac pressure measurements obtained from fetal cardiac catheterization. RESULTS: Surviving banded fetuses (n = 13) had one of two phenotypes: compensatory left ventricular hypertrophy (n = 7) or noncompensatory left ventricular dilatation (n = 6) with hydrops and severe left ventricular dysfunction. All fetuses had elevated left ventricular end-diastolic pressures (mean, 21 mm Hg; range, 14 to 28 mm Hg), which correlated to the gradient across the ascending aorta (mean, 41 mm Hg; range, 28 to 73 mm Hg). In vivo echocardiography findings were incongruous with those at autopsy, and demonstrated preservation of left ventricular growth indices in all fetuses. Endocardial fibroelastosis and myocardial fibrosis were not observed in any banded fetus. CONCLUSIONS: While early gestational obstruction to flow can compromise left ventricular function in the fetus, it does not retard normal growth. Similarly, an elevated left ventricular end-diastolic pressure is not sufficient to cause myocardial fibrosis or endocardial fibroelastosis in the fetus.

Mitogen-activated protein kinase activation and regulation in the pressure-loaded fetal ovine heart.

The mitogen-activated protein (MAP) kinase signaling pathways help to mediate the hypertrophic response of the pressure-loaded adult heart, although their importance in fetal myocardium is less known. The goal of this study was to determine the role the MAP kinase signaling pathways play in regulating the response of the fetal heart to a pressure load. Aortic (Ao) and pulmonary artery (PA) bands were placed in 132-day fetal sheep for 7 days. Protein levels of the total and active (phosphorylated) terminal MAP kinases extracellular signal-regulated kinase (ERK/P-ERK), c-Jun NH(2)-terminal kinase (JNK/P-JNK), and p38/P-p38 and the MAP kinase phosphatases MKP-1, MKP-2, and MKP-3 were made in the right and left ventricular (RV and LV) free walls. In both Ao- and PA-banded animals, total heart weight normalized to body weight was significantly increased, largely due to an increase in RV free wall mass in the Ao-banded animals and an increase in septal mass in the PA-banded fetuses. Total protein levels of the three terminal kinases and of P-ERK and P-JNK remained stable in both groups of banded animals. However, P-p38 was significantly increased in RV and LV of Ao- and PA-banded fetuses. Whereas MKP-1 and MKP-2 protein levels were unchanged following Ao- and PA-banding, MKP-3 protein levels were significantly increased in the RV of the PA-banded animals. These findings indicate that the MAP kinase signaling pathways are active in the fetal heart and help to modulate the response of prenatal myocardium to a pressure load.

Prenatal exposure to maternal undernutrition induces adult cardiac dysfunction.

An adverse environmental experience of the growing fetus may lead to permanent changes in the structure and function of organs that may predispose the individual to chronic diseases in later life; however, nothing is known about the occurrence and mechanisms of heart failure. We employed a rat model in which pregnant dams were fed diets containing either 180 g (normal) or 90 g (low) casein/kg for 2 weeks before mating and throughout pregnancy. The ejection fraction (EF) of the pups exposed to the low-protein (LP) diet was severely depressed in the first 2 weeks of life and was associated with an increase in cardiomyocyte apoptosis. This early depressed cardiac function was followed by progressive recovery and normalization of the EF of the offspring in the LP group. The left ventricular (LV) internal diameters were increased between 24 h and 84 d (12 weeks) of age in the LP-exposed group. Although between 3 d and 2 weeks of age the LV wall of the heart in the LP group was thinner, a progressive increase in LV wall thickness was seen. At 40 weeks of age, although the EF was normal, a two-fold elevation in LV end-diastolic pressure, reduced cardiac output, decreased maximum rates of contraction and relaxation, and reduced mean arterial pressure were observed. Our findings demonstrate that exposure of the developing fetus to a maternal LP diet programs cardiac dysfunction in the offspring in later life.

Intra-uterine growth restriction and the programming of left ventricular remodelling in female rats.

Epidemiological studies link intra-uterine growth restriction (IUGR) with increased incidence of hypertension and cardiac disease in adulthood. Our rat model of IUGR supports this contention and provides evidence for the programming of susceptibility for hypertension in all offspring. Moreover, in the female offspring only, gross anatomical changes (cardiac ventricle to body ratios) and increased left cardiac ventricular atrial natriuretic peptide (ANP) mRNA levels provide evidence for programming of cardiac disease in this gender. The aim of the current study was to measure changes in cardiac tissue that support remodelling that could be implicated in the initiation of hypertrophy. Adult female rats from our IUGR model and age- and sex-matched controls were killed at 12 weeks of age. Left cardiac ventricles were removed and used for monitoring changes in several key genes, Na+,K+-ATPase beta1 protein expression, cardiomyocyte morphology and contractility as well as citrate synthase and aconitase activities. When compared to controls, female offspring of our IUGR rat model exhibit higher expression (mRNA) of ANP and the atrial isoform of the myosin light chain, lower levels of Na+,K+-ATPase beta1 protein, increased cardiomyocyte depth and volume, increased sarcomere length, diminished cardiomyocyte contractility and lower aconitase activity. Female offspring of our IUGR rat model exhibit changes as adults that are consistent with the onset of cardiac remodelling. The decrease in aconitase activity suggests that oxidative stress may be implicated in this response.

Left ventricular myocardial performance in the fetus with severe tricuspid valve disease and tricuspid insufficiency.

We sought to determine whether left ventricular (LV) function is abnormal in a fetus with severe tricuspid valve disease (TVD), and whether it may contribute to the outcome. We measured the LV Tei index (including isovolumic relaxation [IRT], contraction, and ejection times) in 31 fetuses with TVD, compared the data with measurements from 32 normal fetuses, and correlated these measurements with pulmonary morphology and outcome. LV Tei index was significantly greater, ejection times shorter, and IRT longer in TVD compared with controls. The Tei index was highest in fetuses with either pulmonary insufficiency or atresia compared with those with forward flow. Finally, LV Tei index was significantly greater in fetuses with fetal (n = 5) or neonatal (n = 9) demise than in neonatal survivors (n = 7). Global LV performance as assessed by the Tei index is abnormal in TVD and likely contribute to the high mortality associated with TVD.

Fetal cardiac dysfunction in preterm premature rupture of membranes.

BACKGROUND: Preterm premature rupture of membranes (PROM) is associated with one-third of preterm births. In about 50% of preterm PROM cases, the fetuses will elicit a fetal inflammatory response syndrome (FIRS). FIRS is associated with the impending onset of preterm labor, periventricular leukomalacia, neonatal sepsis, and long-term handicap, including the development of bronchopulmonary dysplasia and cerebral palsy. The fetal myocardium is a potential target organ of proinflammatory cytokines released during FIRS. The objective of this study was to determine whether preterm PROM is associated with functional changes in the fetal heart, as determined by fetal echocardiography. METHODS: A retrospective study was conducted to assess the diastolic function of fetuses with preterm PROM with documented microbial invasion of the amniotic cavity (n = 25), preterm PROM without microbial invasion of the amniotic cavity (n = 42), and fetuses from normal pregnancies (control group = 150). Pregnancies with multiple gestation, fetal distress, fetuses that were small for gestational age, and major congenital anomalies were excluded. Fetal echocardiography studies were performed with two-dimensional ultrasound, color Doppler imaging and pulsed Doppler ultrasound. Non-parametric statistics were used for comparisons. A p value of < 0.05 was considered significant. RESULTS: The prevalence of positive amniotic fluid cultures for micro-organisms in patients with preterm PROM was 35.8% (24/67). Ureaplasma urealyticum was the most frequent isolate, either alone (41.7%; 10/24) or with other micro-organisms (29.2%; 7/24). Fetuses with preterm PROM had a higher delta early diastolic filling/atrial contraction (E/A) peak velocity ratio, a higher delta E/A velocity-time integral (VTI) ratio, a lower delta A peak velocity, a lower delta A VTI, and a lower A VTI/total VTI ratio in the mitral valve compared to those with uncomplicated pregnancies. The delta E/A peak velocity ratio was significantly higher and the delta A VTI significantly lower in fetuses with preterm PROM and microbial invasion of the amniotic cavity than in those with preterm PROM without microbial invasion of the amniotic cavity. CONCLUSIONS: Preterm PROM is associated with changes in fetal cardiac function consistent with increased left ventricular compliance. These observations were also noted in fetuses with microbial invasion of the amniotic cavity. Our findings suggest that fetal cardiac function is altered in preterm PROM and, in particular, in cases with intra-amniotic infection.

Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome: candidate selection, technique, and results of successful intervention.

BACKGROUND: Preventing the progression of fetal aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS) requires identification of fetuses with salvageable left hearts who would progress to HLHS if left untreated, a successful in utero valvotomy, and demonstration that a successful valvotomy promotes left heart growth in utero. Fetuses meeting the first criterion are undefined, and previous reports of fetal AS dilation have not evaluated the impact of intervention on in utero growth of left heart structures. METHODS AND RESULTS: We offered fetal AS dilation to 24 mothers whose fetuses had AS. At least 3 echocardiographers assigned a high probability that all 24 fetuses would progress to HLHS if left untreated. Twenty (21 to 29 weeks' gestation) underwent attempted AS dilation, with technical success in 14. Ideal fetal positioning for cannula puncture site and course of the needle (with or without laparotomy) proved to be necessary for procedural success. Serial fetal echocardiograms after intervention demonstrated growth arrest of the left heart structures in unsuccessful cases and in those who declined the procedure, while ongoing left heart growth was seen in successful cases. Resumed left heart growth led to a 2-ventricle circulation at birth in 3 babies. CONCLUSIONS: Fetal echocardiography can identify midgestation fetuses with AS who are at high risk for developing HLHS. Timely and successful aortic valve dilation requires ideal fetal and cannula positioning, prevents left heart growth arrest, and may result in normal ventricular anatomy and function at birth.

Transplantation of fetal cardiomyocytes into infarcted rat hearts results in long-term functional improvement.

Studies have demonstrated the feasibility of transplanting cardiomyocytes after myocardial infarction (MI). However, persistence and effects on left ventricular (LV) function have not been elucidated in long-term studies. Ventricular fetal cardiomyocytes from embryos of both sexes were injected into marginal regions of MI 4 weeks after suture occlusion of the left anterior descending artery in adult female rats. Two and 6 months after transplantation (Tx), engrafted cells were traced by immunohistochemical in situ hybridization for Y chromosomes or bromodeoxyuridine (BrdU) staining, LV dimensions and function were assessed by echocardiography, and LV pressure was assessed ex vivo in a Langendorff perfusion system. Immunohistochemistry for alpha-sarcomeric actin and Y chromosomes revealed the presence of transplanted cells in infarcted host myocardium at both 2 and 6 months. End-diastolic LV diameter markedly decreased after Tx and fractional shortening gradually increased after Tx (31.3 +/- 4.5% before Tx, 45.4 +/- 4.2% at 6 months; p<0.005). Wall area fraction and MI size were unaffected by Tx. In hearts with MI, but not in normal hearts, Tx led to the development of higher pressures (87 +/- 18 versus 38 +/- 8 mmHg, 6 months post-Tx versus nontreated). After catecholamine stimulation, both infarcted and normal hearts developed higher pressures after Tx (p<0.005), ultimately associated with reduced mortality after Tx versus nontreated. Transplanted cardiomyocyte-rich graft cells persist in host myocardium and mediate continuous improvement of LV function and survival in a rat model of MI even during long-term follow-up, possibly involving a catecholamine-sensitive mechanism.

Frequency and quantity of the parvovirus B19 genome in endomyocardial biopsies from patients with suspected myocarditis or idiopathic left ventricular dysfunction.

Parvovirus B19 (PB19) has been identified as a possible cause of myocarditis and heart failure in both children and adult patients. This study used real time PCR analysis, to determine the frequency and to quantify PB19 viral genomes in endomyocardial tissue samples from 80 adult patients with clinically suspected myocarditis or idiopathic left ventricular dysfunction and from 36 controls. Histological (Dallas classification) and immunohistological analyses were performed to detect myocardial inflammation in the endomyocardial biopsies.PB19 genomic DNA was found in nine of 80 patients (11.2%), 4 out of 31 (12.9%) patients with inflammatory infiltrates detected via immunohistological methods and 5 out of 49 (10.2%) patients with left ventricular dysfunction without myocardial inflammation. The copy numbers for PB19 DNA ranged between 30 and 3900 per microg of cellular DNA. Four patients with clinically suspected myocarditis had copy numbers for PB19 DNA of 70, 740, 3400 and 3900, respectively, per microg of cellular DNA in the endomyocardial biopsy. Five patients with idiopathic left ventricular dysfunction had copy numbers for PB19 DNA of 30, 38, 52, 58 and 90, respectively, per microg of cellular DNA in the endomyocardial biopsy. The amplicon of one of the nine positive PCR fragment was sequenced and was found to be fully identical in the highly conserved sequence of published Parvovirus B19 VP1/VP2 genes (NCBI gene bank). In all patients, acute myocarditis was excluded according to the Dallas classification. All biopsies of 36 controls with no history of myocarditis or recent viral infection were negative for myocardial inflammation and parvovirus B19 genomes. In summary, Parvovirus B19 DNA is present within the myocardium of patients with suspected myocarditis and idiopathic left ventricular dysfunction and can be detected and quantified in endomyocardial specimens via real time PCR.