Reference ranges for left, right and interventricular septum indices at 20 to 36+6 weeks of gestation derived using spectral myocardial tissue Doppler on Voluson ultrasound machines.

AIM: To establish reference range values for peak myocardial tissue Doppler velocity (MTD) and myocardial performance index (MPI) of the left ventricle (LV), the right ventricle (RV), and the interventricular septum (IVS) at 20 to 36+6 weeks of gestation using spectral tissue Doppler. MATERIAL AND METHODS: This cross-sectional study was conducted among 360 lowrisk singleton pregnancies. MTD during systole (S'), and early (E') and late diastole (A'), and MPI' were assessed by placing sample volume at the basal segment of the LV free wall, the RV free wall, and the IVS, respectively. Polynomial regression was used to obtain the best-fit curves for MTD and MPI' measurements as a function of gestational age (GA), and adjustments were made using the determination coefficient (R2). Intra- and inter-observer reproducibility was evaluated using the concordance correlation coefficient (CCC). RESULTS: All MTD velocities (cm/s) progressively increased with advancing GA (p<0.0001). Mean LV MTD values were 4.19 to 6.86 for S', 3.52 to 7.22 for E', and 6.85 to 9.19 for A'; mean RV MTD were 4.85 to 7.97 for S', 4.49 to 8.66 for E', and 8.44 to 11.20 for A'; and mean IVS MTD values were 3.75 to 5.78 for S', 3.34 to 5.79 for E', and 5.88 to 7.98 for A'. LV MPI', RV MPI', and IVS MPI' did not significantly change with advancing GA. The CCC values for MTD were predominantly greater than 0.70, while those for MPI' were <0.70. CONCLUSIONS: Reference values for the fetal MTD and MPI' of RV, LV and IVS using tissue Doppler between 20 and 36+6 weeks of gestation were described.

Septal Coronary Venous Mapping to Guide Substrate Characterization and Ablation of Intramural Septal Ventricular Arrhythmia.

OBJECTIVES: This study describes the use of septal coronary venous mapping to facilitate substrate characterization and ablation of intramural septal ventricular arrhythmia (VA). BACKGROUND: Intramural septal VA represents a challenge for substrate definition and catheter ablation. METHODS: Between 2015 and 2018, 12 patients with structural heart disease, recurrent VA, and suspected intramural septal substrate underwent a septal coronary venous procedure in which mapping was performed by advancement of a wire into the septal perforator branches of the anterior interventricular vein. A total of 5 patients with idiopathic VA were also included as control subjects to compare substrate characteristics. RESULTS: Patients were 63 ± 14 years of age, and 11 (92%) were men. Most patients with structural heart disease had nonischemic cardiomyopathy (83%). Six patients underwent ablation for premature ventricular contractions (PVC) and 6 for ventricular tachycardia. All patients had larger septal unipolar voltage abnormalities than bipolar voltage abnormalities (mean area 35.3 ± 16.8 cm2 vs. 10.7 ± 8.4 cm2, respectively; p = 0.01), Patients with idiopathic VA had normal voltage. Septal coronary venous mapping revealed low-voltage, fractionated, and multicomponent electrograms in sinus rhythm in all patients with substrate compared to that in patients with idiopathic VA (amplitude 0.9 ± 0.9 mV vs. 4.4 ± 3.7 mV, respectively; p = 0.007; and duration 147 ± 48 ms vs. 92 ± 10 ms, respectively; p = 0.03). Ablation targeted early activation, pace map match, and/or good entrainment sites from intraseptal recording. Over a mean follow-up of 339 ± 240 days, the PVC and insertable cardioverter-defibrillator therapies burden were significantly reduced (from a mean of 22 ± 11% to 4 ± 8%; p = 0.005; and a mean 5 ± 2 to 1 ± 1; p = 0.001, respectively). Most patients (80%) with idiopathic VA remained arrhythmia free. CONCLUSIONS: In patients with suspected intramural septal VA, mapping of the septal coronary veins may be helpful to characterize the arrhythmia substrate, identify ablation targets, and guide endocardial ablation.

Physicians' Ability to Visually Estimate Left Ventricular Ejection Fraction, Right Ventricular Enlargement, and Paradoxical Septal Motion After a 2-Day Focused Cardiac Ultrasound Training Course.

OBJECTIVE: Focused cardiac ultrasound (FCU) can provide useful information for the management of shock and acute respiratory distress syndrome. This study aimed to determine whether a 2-day focused cardiac ultrasound training course could enable critical care physicians to interpret ultrasound images in terms of left ventricular ejection fraction (LVEF), ratio of right ventricular end-diastolic area to left ventricular end-diastolic area (R/LVEDA), and septal kinetics. DESIGN: A prospective analysis of an image test score. SETTING: Ultrasound training programs in 7 regions across China. PARTICIPANTS: Two hundred forty-seven critical care physicians. INTERVENTIONS: All participants received a 2-day FCU training, including 4 sessions of basic heart function appraisal, 3 sessions of hands-on practice, and 1 session of image interpretation. MEASUREMENTS AND MAIN RESULTS: The post-training total scores were considerably higher than those of pretraining (75.6% v 58.9%, respectively, p < 0.001). After the course, the trainees obtained considerably higher scores on images with LVEF <30% than on images with LVEF 30% to 54% and LVEF ≥55% (100% v 60.0% and 60.0%, respectively, p < 0.001). The trainees obtained considerably higher scores on images with R/LVEDA >1 than on images with R/LVEDA 0.6 to 1 and R/LVEDA <0.6 (90.0% v 80.0% and 80.0%, p = 0.042 and p < 0.001, respectively). The trainees obtained considerably higher scores on images with paradoxical septal movement (PSM) than on images without PSM (100% v 75.0%, respectively, p < 0.001). CONCLUSION: The physicians' abilities to assess LVEF, RV enlargement, and PSM improved after the training course, and they demonstrated more accurate estimations of the most obviously abnormal images.

Subclinical Myocardial Impairment Occurred in Septal and Anterior LV Wall Segments After Anthracycline-Embedded Chemotherapy and did not Worsen During Adjuvant Trastuzumab Treatment in Breast Cancer Patients.

In a previous study of breast cancer patients, we found changes in cardiac function and size during the early stages of adjuvant trastuzumab (Herceptin(®)) therapy. Here we present a subgroup analysis of this patient cohort. This subgroup received a anthracycline-embedded chemotherapy followed by at least 3 months up to 6 months of adjuvant Herceptin(®) therapy. Twenty-seven female breast cancer patients with Her-2/-neu overexpression were studied using conventional echocardiography and 2D speckle tracking. These methods were done before anthracycline-embedded chemotherapy, before adjuvant trastuzumab therapy, and both 3 and 6 months after the start of the therapy (T3, T6). The LV-EF (Simpson biplane) decreased significantly from before the chemotherapy to after the chemotherapy and further decreased after 3 months of trastuzumab therapy (66.2 ± 1.5 vs. 58.7 ± 1.2 vs. 55.6 ± 1.3 vs. 55.9 ± 1.5 %; p < 0.05). The stroke volume index remained constant after chemotherapy (22.0 ± 0.8 vs. 22.6 ± 1.3 ml/m(2); p = 0.9), but increased significantly during trastuzumab therapy (26.7 ± 1.1 and 27.3 ± 1.0 ml/m(2); p < 0.01). Global longitudinal strain exclusively decreased during chemotherapy (-21.0 ± 0.5 vs. -18.9 ± 0.5 %, p < 0.001). Regional longitudinal strain decreased significantly after chemotherapy in septal, anteroseptal, anterolateral, and apex segments. Mitral valve regurgitation increased during the whole treatment, but especially during trastuzumab. Right ventricular function decreased exclusively during chemotherapy. Anthracycline-embedded chemotherapy in patients with breast cancer led to a decrease in LV function, especially of the septal and anterior segments, and did not worsen during adjuvant trastuzumab treatment.

Galen's (130-201 AD) Conceptions of the Heart.

In the 2nd century AD, the prolific Greek physician Galen contributed significantly to the anatomical and physiological knowledge of the cardiovascular system. However his erroneous theory of blood circulation, based on the inaccurate notion that venous blood passes through tiny pores in the heart's septum, moves from the right ventricle to the left, and is mixed with inhaled air from the lungs, was to block any new ideas in this field for more than 1500 years.

Diverse geometric changes related to dynamic left ventricular outflow tract obstruction without overt hypertrophic cardiomyopathy.

BACKGROUND: Dynamic left ventricular (LV) outflow tract (LVOT) obstruction (DLVOTO) is not infrequently observed in older individuals without overt hypertrophic cardiomyopathy (HCM). We sought to investigate associated geometric changes and then evaluate their clinical characteristics. METHODS: A total of 168 patients with DLVOTO, which was defined as a trans-LVOT peak pressure gradient (PG) higher than 30 mmHg at rest or provoked by Valsalva maneuver (latent LVOTO) without fixed stenosis, were studied. Patients with classical HCM, acute myocardial infarction, stress induced cardiomyopathy or unstable hemodynamics which potentially induce transient-DLVOTO were excluded. RESULTS: Their mean age was 71 ± 11 years and 98 (58%) patients were women. Patients were classified as pure sigmoid septum (n = 14) if they have basal septal bulging but diastolic thickness less than 15 mm, sigmoid septum with basal septal hypertrophy for a thickness ≥15 mm (n = 85), prominent papillary muscle (PM) (n = 20) defined by visually large PMs which occluded the LV cavity during systole or 1/2 LVESD, or as having a small LV cavity with concentric remodelling or hypertrophy (n = 49). The prominent PM group was younger, had a higher S' and lower E/e' than other groups. In all groups, a higher peak trans-LVOT PG was related (p < 0.10) to higher E/e', systolic blood pressure, relative wall thickness, and pulmonary arterial systolic pressure. In multivariate analysis, resting trans-LVOT PG correlated to pulmonary arterial pressure (ß = 0.226, p = 0.019) after adjustment for systolic blood pressure, relative wall thickness, and E/e'. CONCLUSIONS: DLVOTO develops from various reasons, and patients with prominent PMs have distinct characteristics. We suggest to use DLVOTO-relieving medication might reduce pulmonary pressure in this group of patients.

The degree of left atrial structural remodeling impacts left ventricular ejection fraction in patients with atrial fibrillation.

OBJECTIVES: The extent of left atrial (LA) wall structural remodeling (fibrosis) detected by late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) is correlated with advanced atrial fibrillation (AF). The concomitant occurrence of AF and left ventricular (LV) dysfunction is not uncommon. We studied the effect of LA fibrosis, a confounder of both AF and LV dysfunction, on LV ejection fraction (EF). STUDY DESIGN: For the analysis, we identified and included 384 patients from our retrospective AF database who underwent LGE-MRI and transthoracic echocardiography prior to AF ablation. Based on the degree of LA fibrosis, patients were categorized into four stages as: Utah 1 (<5% LA fibrosis), Utah 2 (5-20% fibrosis), Utah 3 (20-35% fibrosis), and Utah 4 (>35% fibrosis). RESULTS: The average pre-ablation LVEF was 60.5%±8.5% (n=24) in Utah stage 1 patients, 55.7%±10.3% (n=240) in Utah stage 2 patients, 51.7±11.5% (n=90) in Utah stage 3 patients, and 48.9%±11.6% (n=30) in Utah stage 4 patients (p<0.001, one-way ANOVA). The percentage of LA fibrosis was significantly negatively correlated to LVEF pre-ablation in a univariate analysis (p<0.001). In a multivariate model accounting for age, gender, AF type, and comorbidities such as diabetes and hypertension, Utah stage remained a significant predictor of pre-ablation EF (p<0.001). CONCLUSION: Patients with extensive LA fibrosis appear to have depressed LV function pre-ablation, suggesting that structural remodeling in the LA may also be triggering and promoting remodeling within the ventricular myocardium.

The relationship between longitudinal, lateral, and septal contribution to stroke volume in patients with pulmonary regurgitation and healthy volunteers.

Septal systolic motion is towards the left ventricle (LV) in healthy hearts. Patients with pulmonary regurgitation (PR) and right ventricular (RV) volume overload have systolic septal motion toward the RV. This may affect the longitudinal contribution from atrioventricular plane displacement (AVPD) and septal and lateral contribution to stroke volume (SV). The study aimed to quantify these contributions to SV in patients with PR. Cardiac magnetic resonance imaging was used for assessment of cardiac volumes. Patients (n = 30; age 9-59 yr) with PR due to surgically corrected tetralogy of Fallot and 54 healthy controls (age 10-66 yr) were studied. Longitudinal contribution to RVSV was 47 ± 2% (means ± SE) in patients with PR and 79 ± 1% in controls (P < 0.001). Lateral contribution to RVSV and LVSV was 40 ± 1 and 62 ± 2% in patients and 31 ± 1 and 36 ± 1% in controls (P < 0.001 for both). Septal motion contributed to RVSV by 8 ± 1% in patients and by 7 ± 1% to LVSV in controls (P < 0.001). PR patients have decreased longitudinal contribution to RVSV and increased lateral pumping, resulting in larger outer volume changes and septal motion towards the RV. The changes in RV pumping physiology may be explained by RV remodeling resulting in lower systolic inflow of blood into the right atrium in relation to SV. This avoids the development of pendulum volume between the caval veins and right atrium, which would occur in PR patients if longitudinal contribution to SV was preserved. Decreased AVPD suggests that tricuspid annular excursion, a marker of RV function, is less valid in these patients.

Synchronous intra-myocardial ventricular pacing without crossing the tricuspid valve or entering the coronary sinus.

Ventricular pacing is most commonly performed at the right ventricular (RV) apex. This is not without risk as placement requires crossing the tricuspid valve (TV) and may cause valvular dysfunction and dyssynchronous activation of the ventricles. The fact that the tricuspid valve lies more apically than the mitral valve allows for the possibility of pacing the ventricles from the right atrium (RA) via the "atrio-ventricular septum" without crossing the TV or entering the coronary sinus (CS). In order to mitigate far field activation inherent to current pacing technology, we constructed a novel lead in which the cathode and anode are both intra-myocardial. We demonstrate safety and efficacy of this novel lead for ventricular pacing at the atrio-ventricular septum in canines, including improved synchronous activation of both ventricles, improved differentiation in ventricular versus atrial sensing, while providing reliable ventricular capture, opening novel and a potentially safer alternative to human cardiac resynchronization therapy.

Value of annular M-mode displacement vs tissue Doppler velocities to assess cardiac function in intrauterine growth restriction.

OBJECTIVE: To compare the ability of two different methods for longitudinal annular motion measurement, M-mode and tissue Doppler imaging (TDI), to demonstrate cardiac dysfunction in intrauterine-growth-restricted (IUGR) fetuses. METHODS: Cardiac longitudinal annular motion in the basal free wall of the left ventricle (mitral annulus), interventricular septum and tricuspid annulus was assessed in 23 early-onset IUGR cases and 43 controls by TDI (annular peak velocities) and M-mode (displacement). RESULTS: All annular parameters were significantly decreased in the IUGR group with respect to controls using both methods. M-mode showed a trend towards equal performance as classifier between cases and controls, as compared to TDI, mainly in the tricuspid annulus. CONCLUSIONS: Both M-mode and TDI demonstrate annular motion changes and consequently cardiac dysfunction in IUGR fetuses. M-mode imaging is simpler to perform and could be as sensitive as TDI for detecting subtle changes.

Interaction between the septum and the left (right) ventricular free wall in order to evaluate the effects on coronary blood flow: numerical simulation.

Mathematical modelling of the cardiovascular system (CVS) can help in understanding the complex interactions between both the ventricles and the septum. By describing the behaviour of the left (right) ventricular free wall, atria and septum using the variable elastance models, it is possible to reproduce their interactions. By relating the mechanical properties of both atria and both ventricles to the electrocardiogram (ECG) signal, it is possible to analyse the effects produced by different ECG delay on haemodynamic parameters. In the cardiovascular field, the incorrect interactions between septum and both ventricular free walls are based on many pathological conditions, i.e. symptomatic heart failure resulting from systolic dysfunction, ischemic dilated cardiomyopathy, and so on. The possible corrections that can be induced on the QRS complex duration in the ECG signal (i.e. cardiac resynchronisation therapy, CRT) can produce benefits improving the clinical status of the patient. The aim of this work was to evaluate, using our numerical simulator of the CVS, the effects induced on coronary blood flow (CBF) and aortic pressure using different ECG times, intra-ventricular and inter-ventricular delays. The results were obtained by reproducing the circulatory baseline and CRT conditions of seven patients described in literature. Haemodynamic simulated results are in accordance with literature data. Also the controversial results on CBF, in presence of CRT, are consistent with those described in the literature.

Early diastolic mitral annular velocity at the interventricular septal annulus correctly reflects left ventricular longitudinal myocardial relaxation.

AIMS: Early diastolic mitral annular velocity (e') obtained by tissue Doppler imaging (TDI) is widely used to evaluate left ventricular (LV) diastolic function based on the assumption that it reflects myocardial relaxation in the long-axis direction. In this study, we aimed to determine whether or not e' truly reflects early diastolic longitudinal myocardial relaxation, and which is the most useful for evaluating LV diastolic function among e' measured at the interventricular-septal annulus (IS-e'), that measured at the lateral annulus (LW-e') or their mean value (M-e'). METHODS AND RESULTS: IS-e', LW-e', and M-e' were measured using colour TDI in 15 patients with hypertrophic cardiomyopathy, 13 patients with hypertension, and 19 control subjects. Using two-dimensional speckle-tracking imaging, early diastolic myocardial strain rates (SR(E)) were measured for the IS (IS-SR(E)), LW (LW-SR(E)), and entire LV myocardium (G-SR(E)). IS-e' was excellently correlated with IS-SR(E) (r = 0.90, P < 0.001); the correlation was better than that between LW-e' and LW-SR(E) (r = 0.75, P < 0.001). IS-e' and M-e' were well correlated with G-SR(E) (r = 0.88, P < 0.001 and r = 0.86, P< 0.001, respectively) and with LV early diastolic flow propagation velocity (FPV) (r = 0.77, P < 0.001 and r = 0.78, P < 0.001, respectively). The correlations of LW-e' to G-SR(E) (r = 0.80, P < 0.001) and FPV (r = 0.75, P < 0.001) did not reach this level. CONCLUSION: IS-e' well reflected LV longitudinal myocardial relaxation and LV diastolic function, and was found to be more useful in evaluating LV diastolic function than LW-e'.

Direct visualization of the slow pathway using voltage gradient mapping: a novel approach for successful ablation of atrioventricular nodal reentry tachycardia.

AIMS: Ablation of atrioventricular nodal reentry tachycardia (AVNRT) has become treatment of choice because of a high success and low complication rate. Most ablations are successful in utilizing an anatomic approach, but anatomic variance, unusual pathway locations, or multiple pathways may complicate the procedure. Visualization of the slow pathway could expedite ablation success and enhance safety. Our purpose is to determine whether voltage gradient mapping can directly image the slow pathway and aid successful ablation of AVNRT. METHODS AND RESULTS: Three-dimensional voltage maps of the right atrial septum were constructed from intracardiac recordings obtained by contact mapping. Voltage values were adjusted until low-voltage bridging was observed within the Triangle of Koch. Forty-eight consecutive patients undergoing ablation for inducible AVNRT, underwent voltage gradient mapping. The slow pathway was identified in all 48 patients via its corresponding low-voltage bridge. Ablation of the slow pathway associated low-voltage bridges in 48 patients was successful in preventing reinduction following the first lesion in 43 of 48 patients. Five patients had multiple slow pathways and >1 lesion was required to prevent reinduction. Repeat mapping confirmed the absence of low-voltage connections previously observed in all 48 patients. CONCLUSION: Voltage gradient mapping can assist in visualization of the slow pathway. Ablation of the associated low-voltage bridge results in loss of slow pathway function and significant changes in the post-ablation voltage map. We conclude that voltage gradient mapping offers the ability to target the slow pathway for successful ablation.

Alternative endocardial sites for artificial cardiac stimulation.

The conventional right ventricular stimulation can be associated with deleterious effects on cardiac function. The need for a more physiological artificial cardiac stimulation is undoubtedly one of the most important points in the area of cardiac electrotherapy. The programming algorithms for the maintenance of adequate atrioventricular conduction, the stimulation of alternative endocardial sites and the cardiac resynchronization therapy are used with the objective of attaining these goals. The stimulation of the bundle of His and the septal stimulation have been studied as alternative endocardial sites for the positioning of the electrode on the right ventricle. The septal stimulation represents a simple and practical alternative, with no additional costs involved and with potential benefits in decreasing the deleterious effects of the right ventricular stimulation. However, this alternative site involves a heterogeneous group of patients and presents conflicting results regarding its long-term clinical benefit. This article reviews the scientific evidence on the alternative sites for right ventricular stimulation, with emphasis on the safety of the procedure, the measurement of the electrophysiological parameters, assessment of the left ventricular function and the clinical follow-up of patients.

Sítios endocárdicos alternativos na estimulação cardíaca artificial / Alternative endocardial sites for artificial cardiac stimulation / Sitios endocárdicos alternativos en la estimulación cardíaca artificial

A estimulação ventricular direita convencional pode estar associada a efeitos deletérios sobre a função cardíaca. A necessidade de uma estimulação cardíaca artificial mais fisiológica é, indiscutivelmente, um dos pontos mais importantes na área da eletroterapia cardíaca. Os algoritmos de programação para a manutenção da condução atrioventricular própria, a estimulação de sítios endocárdicos alternativos e a terapia de ressincronização cardíaca são utilizados com o intuito de alcançar este objetivo. A estimulação do feixe de His e a estimulação septal têm sido estudadas como sítios endocárdicos alternativos para o posicionamento do eletrodo no ventrículo direito. A estimulação septal representa uma alternativa simples, prática e sem custos adicionais e com potenciais benefícios na redução dos efeitos deletérios da estimulação do ventrículo direito. Entretanto, esse sítio alternativo envolve um grupo heterogêneo de pacientes e apresenta resultados conflitantes quanto ao seu benefício clínico a longo prazo. Este artigo faz uma revisão das evidências científicas sobre os sítios alternativos de estimulação ventricular direita, com ênfase na segurança do procedimento, na medida dos parâmetros eletrofisiológicos, na avaliação da função ventricular esquerda e no acompanhamento clínico dos pacientes.

The conventional right ventricular stimulation can be associated with deleterious effects on cardiac function. The need for a more physiological artificial cardiac stimulation is undoubtedly one of the most important points in the area of cardiac electrotherapy. The programming algorithms for the maintenance of adequate atrioventricular conduction, the stimulation of alternative endocardial sites and the cardiac resynchronization therapy are used with the objective of attaining these goals. The stimulation of the bundle of His and the septal stimulation have been studied as alternative endocardial sites for the positioning of the electrode on the right ventricle. The septal stimulation represents a simple and practical alternative, with no additional costs involved and with potential benefits in decreasing the deleterious effects of the right ventricular stimulation. However, this alternative site involves a heterogeneous group of patients and presents conflicting results regarding its long-term clinical benefit. This article reviews the scientific evidence on the alternative sites for right ventricular stimulation, with emphasis on the safety of the procedure, the measurement of the electrophysiological parameters, assessment of the left ventricular function and the clinical follow-up of patients.

La estimulación ventricular derecha convencional puede estar asociada a efectos deletéreos sobre la función cardíaca. La necesidad de una estimulación cardíaca artificial más fisiológica es, indiscutiblemente, uno de los puntos más importantes en el área de la electroterapia cardíaca. Los algoritmos de programación para la manutención de la conducción atrioventricular propia, la estimulación de sitios endocárdicos alternativos y la terapia de resincronización cardíaca son utilizados con el propósito de alcanzar este objetivo. La estimulación del haz de His y la estimulación septal han sido estudiadas como sitios endocárdicos alternativos para el posicionamiento del electrodo en el ventrículo derecho. La estimulación septal representa una alternativa simple, práctica y sin costos adicionales y con potenciales beneficios en la reducción de los efectos deletéreos de la estimulación del ventrículo derecho. Entre tanto, ese sitio alternativo envuelve un grupo heterogéneo de pacientes y presenta resultados conflictivos en cuanto a su beneficio clínico a largo plazo. Este artículo hace una revisión de las evidencias científicas sobre los sitios alternativos de estimulación ventricular derecha, con énfasis en la seguridad del procedimiento, en la medida de los parámetros electrofisiológicos, en la evaluación de la función ventricular izquierda y en el control clínico de los pacientes.

Autologous cardiomyotissue implantation promotes myocardial regeneration, decreases infarct size, and improves left ventricular function.

BACKGROUND: Cell therapy for myocardial infarction (MI) may be limited by poor cell survival and lack of transdifferentiation. We report a novel technique of implanting whole autologous myocardial tissue from preserved myocardial regions into infarcted regions. METHODS AND RESULTS: Fourteen rats were used to optimize cardiomyotissue size with peritoneal wall implantation (300 µm identified as optimal size). Thirty-nine pigs were used to investigate cardiomyotissue implantation in MI induced by left anterior descending balloon occlusion (10 animals died; male-to-female transplantation for tracking with in situ hybridization for Y chromosome, n=4 [2 donors and 2 MI animals]; acute MI implantation cohort at 1 hour, n=13; and healed MI implantation at 2 weeks, n=12). Assessment included echocardiography, magnetic resonance imaging, hemodynamics, triphenyltetrazolium chloride staining, and histological and molecular analyses. Tracking studies demonstrated viable implants with donor cells interspersed in the adjacent myocardium with gap junctions and desmosomes. In the acute MI cohort, treated animals compared with controls had improved perfusion by magnetic resonance imaging (1.2±0.01 versus 0.86±0.05; P<0.01), decreased MI size (magnetic resonance imaging: left ventricle, 2.2±0.5% versus 5.4±1.5%, P=0.04; triphenyltetrazolium chloride: anterior wall, 10.3±4.6% versus 28.9±5.8%, P<0.03), and improved contractility (dP/dt, 1235±215 versus 817±817; P<0.05). In the healed MI cohort, treated animals had less decline in ejection fraction between 2 and 4 week assessment (-3±4% versus -13±-4%; P<0.05), less decline in ±dP/dt, and smaller MI (triphenyltetrazolium chloride, 21±11% versus 3±8%; P=0.006) than control animals. Infarcts in the treated animals contained more mdr-1(+) cells and fewer c-kit(+) cells with a trend for decreased expression of matrix metalloproteinase-2 and increased expression of tissue inhibitor of metalloproteinase-2. CONCLUSION: Autologous cardiomyotissue implanted in an MI area remains viable, exhibits electromechanical coupling, decreases infarct size, and improves left ventricular function.

Left ventricular myocardial velocities and deformation indexes in top-level athletes.

BACKGROUND: The aim of this study was to define the range of left ventricular (LV) velocities and deformation indexes in highly trained athletes, analyzing potential differences induced by different long-term training protocols. METHODS: Standard echocardiography, pulsed-wave tissue Doppler echocardiography, and two-dimensional strain echocardiography of the interventricular septum and lateral wall were performed in 370 endurance athletes and 280 power athletes. Using pulsed-wave tissue Doppler, the following parameters of myocardial function were assessed: systolic peak velocities (S(m)), early (E(m)) and late (A(m)) diastolic velocities, and the E(m)/A(m) ratio. By two-dimensional strain echocardiography, peaks of regional systolic strain and LV global longitudinal strain were calculated. RESULTS: LV mass index and ejection fraction did not significantly differ between the two groups. However, power athletes showed an increased sum of wall thicknesses (P < .01) and relative wall thickness, while LV stroke volume and LV end-diastolic diameter (P < .001) were greater in endurance athletes. By pulsed-wave tissue Doppler analysis, E(m) and E(m)/A(m) at both the septal and lateral wall levels were higher in endurance athletes. By two-dimensional strain echocardiography, myocardial deformation indexes were comparable between the two groups. E(m)/A(m) ratios ≥ 1 were found in the overall population, while 90 % of athletes had an E(m) ≥ 16 cm/sec, S(m) ≥ 10 cm/sec, and global longitudinal strain ≤ -16%. Multivariate analyses evidenced independent positive association between Em peak velocity and LV end-diastolic volume (P < .001) and an independent correlation of global longitudinal strain with the sum of LV wall thicknesses (P < .005). CONCLUSIONS: This study describes the full spectrum of systolic and diastolic myocardial velocities and deformation indexes in a large population of competitive athletes.

A-V nodal artery anatomy and relations to the posterior septal space and its contents.

BACKGROUND AND AIM: Radiofrequency catheter ablation treats resistant nodal re-entrant tachycardia but carries a risk to AV conduction system and its vessels. We aimed to study the origin of the A-V nodal artery (AVNA) and its course within the posterior septal space (PSS). METHODS: Twenty embalmed human hearts of both sexes (16 males) age, 25-60 years, were dissected to study the PPS and its arteries down to their destination. RESULTS: The PSS is a four sided pyramidal space, at the crux of the heart, with its base made of the pericardium. It is made of four; right upper and lower and left upper and lower walls corresponding to the right atrium and ventricle and left atrium and ventricle, respectively. The right coronary artery (RCA) crossed the base from the right to the left angle, to lie inferior and adherent to the terminal part of the coronary sinus (CS). The posterior interventricular artery, the ventricular branches of the RCA, the middle cardiac vein and the ventricular veins, all crossed the base of the space to their final destination. AVNA originated from either the RCA itself or one of its branches. Double AVNA was encountered in 14 specimens with the upper artery larger and passed between the right and left atria and the lower artery smaller and crossed the space adjacent to the right ventricle. CONCLUSIONS: These findings highlight the importance of the PSS and its structural relations, in particular to the AVNA, that should be considered during various interventional procedures.

Three-wall segment (TriSeg) model describing mechanics and hemodynamics of ventricular interaction.

A mathematical model (TriSeg model) of ventricular mechanics incorporating mechanical interaction of the left and right ventricular free walls and the interventricular septum is presented. Global left and right ventricular pump mechanics were related to representative myofiber mechanics in the three ventricular walls, satisfying the principle of conservation of energy. The walls were mechanically coupled satisfying tensile force equilibrium in the junction. Wall sizes and masses were rendered by adaptation to normalize mechanical myofiber load to physiological standard levels. The TriSeg model was implemented in the previously published lumped closed-loop CircAdapt model of heart and circulation. Simulation results of cardiac mechanics and hemodynamics during normal ventricular loading, acute pulmonary hypertension, and chronic pulmonary hypertension (including load adaptation) agreed with clinical data as obtained in healthy volunteers and pulmonary hypertension patients. In chronic pulmonary hypertension, the model predicted right ventricular free wall hypertrophy, increased systolic pulmonary flow acceleration, and increased right ventricular isovolumic contraction and relaxation times. Furthermore, septal curvature decreased linearly with its transmural pressure difference. In conclusion, the TriSeg model enables realistic simulation of ventricular mechanics including interaction between left and right ventricular pump mechanics, dynamics of septal geometry, and myofiber mechanics in the three ventricular walls.