Pulsative venous return from the branchial vessels to the heart of the Mytilus galloprovincialis supports the constant-volume mechanism.

In bivalves and gastropods, ventricle contraction causes a negative pressure in the auricles, and increases venous return from the afferent oblique vein (AOV): the constant-volume (CV) mechanism. The flow in the AOV should be a pulsative flow synchronized with the ventricular contraction. The flow in the heart and adjacent vessels of the Mytilus galloprovincialis were measured by magnetic resonance imaging to confirm this hypothesis. Under a regular heartbeat, pulsative flows in the AOV and branchial vessels (BVs) were almost completely synchronized with the flow in the aorta, while filling in the ventricle was in the opposite phase. Flows in the BVs were directed to the posterior direction, and a pair of BVs in the gill axes (the efferent BVs) were connected to the AOV. Based on the images of the whole pathway of the AOV in an oblique slice, we confirmed that haemolymph flow was evoked from the efferent BVs, and flow into the ventricle via the auricle was completed in a single heartbeat. Therefore, the walls of the AOV and BVs could resist negative transmural pressure caused by the ventricular contraction. In conclusion, the auricle, the AOV and the BVs, including the gill filaments, act as a suction pump. The pulsative venous return is driven by the negative pressure of the AOV as in the CV mechanism, and the negative pressure in the efferent BVs could draw haemolymph from the sinus via the gill and the afferent BVs. Therefore, the Mytilus can start and stop its heartbeat ad libitum.

An Unexpected Diagnostic Twist in an Elderly Patient: No Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is considered to be the dominant cause of dyspnea and pulmonary hypertension (PH) in elderly patients with preserved left ventricular systolic function and cardiovascular comorbidities. However, it is important to keep in mind that left ventricular diastolic dysfunction is not the only possible cause of PH in cases of late-onset clinical manifestation. A multiparametric approach is essential for accurate diagnosis and therapeutic decision-making. A 74-year-old patient was admitted due to progressive dyspnea and suspicion of PH. Given the patient's risk profile, HFpEF and concomitant post-capillary PH were anticipated. Despite negative findings on CT angiography and transesophageal echocardiography, right heart catheterization was performed, revealing discrepant oxygen saturations in the superior vena cava and right atrium. A partial anomalous pulmonary venous return and an atrial septal defect were identified through cardiac magnetic resonance imaging.

An interactive simulator to deepen the understanding of Guyton's venous return curve.

Mean circulatory filling pressure, venous return curve, and Guyton's graphical analysis are basic concepts in cardiovascular physiology. However, some medical students may not know how to view and interpret or understand them adequately. To deepen students' understanding of the graphical analysis, in place of having to perform live animal experiments, we developed an interactive cardiovascular simulator, as a self-learning tool, as a web application. The minimum closed-loop model consisted of a ventricle, an artery, resistance, and a vein, excluding venous resistance. The simulator consists of three modules: setting (parameters and simulation modes), calculation, and presentation. In the setting module, the user can interactively customize model parameters, compliances, resistance, Emax of the ventricular contractility, total blood volume, and unstressed volume. The hemodynamics are calculated in three phases: filling (late diastole), ejection (systole), and flow (early diastole). In response to the user's settings, the simulator graphically presents the hemodynamics: the pressure-volume relations of the artery, vein, and ventricle, the venous return curves, and the stroke volume curves. The mean filling pressure is calculated at approximately 7 mmHg at the initial setting. The venous return curves, linear and concave, are dependent on the venous compliance. The hemodynamic equilibrium point is marked on the crossing point of venous return curve and the stroke volume curve. Users can interactively do discovery learning, and try and confirm their interests and get their questions answered about hemodynamic concepts by using the simulator.

Cor Triatriatum Dexter With a Sinus Venosus Atrial Septal Defect in a 50-Year-Old Woman: A Case Report.

The diagnosis of atrial septal defect (ASD) may be delayed until adulthood or even later in life as it is a well-tolerated congenital heart disease. If patients are not examined and investigated well in childhood, the diagnosis may be delayed until later in adulthood when patients present with palpitations and sometimes dyspnea due to the right chambers dilatation from right ventricular volume overload. In this report, we present a case of a 50-year-old female patient with symptoms of heart failure and atrial fibrillation who was found to have dilated right cardiac chambers, dilated pulmonary artery, severe tricuspid regurgitation, pulmonary hypertension, and a pulmonary-to-systemic flow ratio (Qp/Qs) of more than 1.5 by transthoracic echocardiography and Doppler, indicating left to right shunt at the atrial level. However, transthoracic echocardiography could not visualize the defect, and two-dimensional (2D) transesophageal echocardiography was done in this patient and documented the presence of a sinus venosus ASD with an incomplete cor triatriatum dexter membrane; all four pulmonary veins were identified going to the left atrium. Since the presence of an incomplete cor triatriatum dexter membrane (despite causing no symptoms) makes the percutaneous closure of the sinus venosus ASD and the percutaneous repair of tricuspid regurgitation very difficult, we decided to advise surgical ASD closure and tricuspid valve repair for the patient.

Right S3 segmentectomy for lung cancer with partial anomalous pulmonary venous return in the right upper pulmonary vein: A case report.

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital malformation where the pulmonary vein partially refluxes into the venous system. Here, we present the first robotic-assisted right S3 segmentectomy in a 70-year-old male with early-stage lung cancer and PAPVR in the right upper pulmonary vein. The patient, with suspected primary lung cancer (11 mm diameter, pure solid appearance in right S3 segment), exhibited clinical stage T1bN0M0 stage IA2. Preoperative computed tomography revealed severe lung emphysema, and right V1-3 returned directly to the superior vena cava. However, no signs of right-sided heart failure were observed, and echocardiogram was normal with a pulmonary-to-systemic blood flow ratio of 1.4. Successful robot-assisted right S3 segmentectomy with hilar nodal dissection was performed, and the patient was discharged on the sixth postoperative day without complications. One year postoperatively, there has been no recurrence of lung cancer or respiratory/right-sided heart failure symptoms.

Rare case of total anomalous pulmonary venous return into the right atrium in situs solitus.

We report an uncommon case report of total anomalous pulmonary venous returns into the right atrium at the base of the superior caval vein's ostium without a sinus venosus defect, in situs solitus, without vertical vein or a posterior pulmonary venous confluence.

From Other Journals: A Review of Recent Articles by Our Editorial Team.

In this review, we provide a brief description of recently published articles addressing topics relevant to pediatric cardiologists. Our hope is to provide a summary of the latest articles published recently in other journals in our field. The articles address (1) A new index for prenatal diagnosis of total anomalous pulmonary venous return, (2) Outcomes of patients with Tetralogy of Fallot after pulmonary valve replacement (PVR), and (3) Short-term outcomes of the self expanding Harmony valve for transcatheter PVR.

The value of circular reasoning: what Harvey taught and we forgot.

William Harvey discovered that the cardiovascular system is a closed hydraulic circle. Since that discovery, many haemodynamic models have strayed by dividing the circulation into segments, which can be misleading. An alternative model is presented that both preserves circular hydraulics and provides a comprehensive picture of overall cardiovascular function using a novel cardiovascular vector graphic. The practical value of this approach resides in its ease of visualising critical physiological variables and ease of predicting and communicating how changes in those variables affect function.

Sex-Specific Limitation of Cardiac Capacity During the Adult Life Span: Return to Fundamental Structure and Function.

Physiology underlying reduced cardiac pumping capacity in women compared with men and its interaction with aging remains unresolved. Herein, the pressure gradient (PG) driving venous return was manipulated to evidence whether cardiac structure and/or function explain sex differences in cardiac capacity. Healthy women/men matched by age and physical activity were included within young (n = 40, age = 25 ±â€…4 years) and older (n = 55, age = 60 ±â€…8 years) groups. Cardiac volumes/output (Q) were assessed up-to-peak exercise under 2 hemodynamic conditions ("low"/"high" PG between lower/upper body). Main outcomes included sex differences in delta ("high" - "low" PG) left ventricular (LV) end-diastolic volume (∆LVEDV), stroke volume (∆SV), and Q (∆Q). In young individuals, "high"-PG increased exercise LVEDV and SV in men (p ≤ .002), but not in women (p ≥ .562), relative to "low"-PG (control condition). Accordingly, peak ∆LVEDV, ∆SV, and ∆Q were enhanced in young men versus young women (p ≤ .019). Notwithstanding, right/left atrial volumes during exercise were similarly increased by "high"-PG in both young sexes (p ≤ .007). "High"-PG exclusively prolonged moderate exercise LV filling time in young men (p ≤ .036). In older individuals, "high"-PG did not modify exercise cardiac volumes and reduced LV diastolic function (p ≤ .049). In conclusion, the female young heart is unrestrained by venous return or structural factors external to the myocardium. As determined during moderate exercise, impaired LV filling time lengthening limits female-specific cardiac capacity. With older age, cardiac chambers are not distended and LV relaxation is impaired with increased PG in both sexes. During early but not late adulthood, a functional LV limitation may explain sex differences in cardiac capacity.

Mean systemic filling pressure and venous return to assess the effects of passive leg raising and volume expansion in acute circulatory failure patients: a posthoc analysis of a multi-centre prospective study.

BACKGROUND: The main aim of the study was to investigate the behaviours of the mean systemic filling pressure (Pmsf), calculated by the mathematical method, and its derived variables of venous return after volume expansion (VE) and passive leg raising (PLR), with analysis according to fluid and PLR responsiveness. METHODS: This was a post-hoc analysis of a multicentre prospective study. We included 202 mechanically ventilated patients with acute circulatory failure. Pmsf, dVR (difference between Pmsf and central venous pressure [CVP]), and resistance to venous return (RVR) were calculated before/after PLR and before/after VE. Fluid- and PLR-responsiveness were defined according to the increase in cardiac index (CI) >15% after VE and >10% after PLR, respectively. RESULTS: Pmsf increased significantly after VE and PLR in both fluid and PLR-responder and non-responder groups. In fluid-responder patients, the increase in dVR was significantly higher than in non-responder group (1.5 [IQR:1.0-2.0] vs. 0.3 [IQR:-0.1-0.6] mmHg, p < 0.001) because of the larger increase in CVP relative to Pmsf in the non-responder group. The same findings were observed after PLR. RVR significantly decreased only in the fluid-responder and PLR-responder groups after VE and PLR. CONCLUSIONS: Venous return, derived from the mathematical model, increased in preload-dependent patients after VE and PLR because of the larger increases in Pmsf relative to CVP and the decreases in RVR. In preload-independent patients, VR did not change because of the larger rise in CVP compared to Pmsf after VE and PLR. These findings agree with the physiological model of circulation described by Guyton.

ACR Appropriateness Criteria® Congenital or Acquired Heart Disease.

Pediatric heart disease is a large and diverse field with an overall prevalence estimated at 6 to 13 per 1,000 live births. This document discusses appropriateness of advanced imaging for a broad range of variants. Diseases covered include tetralogy of Fallot, transposition of great arteries, congenital or acquired pediatric coronary artery abnormality, single ventricle, aortopathy, anomalous pulmonary venous return, aortopathy and aortic coarctation, with indications for advanced imaging spanning the entire natural history of the disease in children and adults, including initial diagnosis, treatment planning, treatment monitoring, and early detection of complications. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Persistent Patent Vertical Vein After Repair of Total Anomalous Pulmonary Venous Connection (TAPVR): A Rare Cause of Hypoxemia Post-Fontan Procedure.

Vertical vein (VV) ligation during total anomalous pulmonary venous return (TAPVR) repair is controversial. While some surgeons prefer ligation of the VV to prevent adverse sequelae of shunting across it and to promote flow through the newly created anastomosis, others leave it to serve as a "pop off valve" to the left heart structures, which are believed to be hypoplastic and noncompliant, presumably contributing to a more favorable post-operative outcome. We report two patients post-Fontan procedure, who underwent cardiac catheterization to explore the etiology of hypoxia and were found to have a persistent VV responsible for right to left shunting. Both patients underwent closure of the VV with improvement in the cyanosis and clinical course. These cases provide evidence supporting surgical ligation of the VV at the time of TAPVR repair, especially in patients with single ventricle.

The effect of lower limb strengthening exercise on orthostatic blood pressure and the skeletal muscle pump in older people with orthostatic hypotension.

INTRODUCTION: Activation of muscles during standing is recommended to activate the skeletal muscle pump, increasing venous return and increasing blood pressure (BP) in people with orthostatic hypotension (OH). AIM: The aim of this study is to determine if increasing the strength of the lower limb muscles can improve the effectiveness of the venous pump and postural BP in older people with OH. METHODS: Ten older people with OH underwent an 8-week lower limb strengthening intervention. Repeated measurements of orthostatic BP, calf venous ejection fraction (EF) and muscle strength took place before, during and after intervention. RESULTS: The intervention increased calf muscle strength by 21% (interquartile range: 18-28), p = 0.018, from a median baseline of 38 (34-45) kg. Participants had normal levels of venous EF 64% (51-75) at baseline, with little to no venous reflux. The median ejection volume at baseline was 44 (36-58) mL per calf. Despite increasing muscle strength, venous EF did not increase (percentage change -10% (-16 to 24), p = 0.8) and systolic BP drop did not improve (percentage change 0% (-17 to 16), p = 1.0). Similarly, visual analysis of individual case-series trends revealed increasing muscle strength with no clinically meaningful change in EF or orthostatic BP. CONCLUSIONS: Muscle strengthening exercise does not increase the effectiveness of the skeletal muscle pump and is not an efficacious intervention for OH. As there is little to no venous pooling in the calf during standing in older people with OH, below knee compression is unlikely to be clinically effective.

The Impact of Head Position on Neurological and Histopathological Outcome Following Controlled Automated Reperfusion of the Whole Body (CARL) in a Pig Model.

Introduction: Based on extracorporeal circulation, targeted reperfusion strategies have been developed to improve survival and neurologic recovery in refractory cardiac arrest: Controlled Automated Reperfusion of the whoLe Body (CARL). Furthermore, animal and human cadaver studies have shown beneficial effects on cerebral pressure due to head elevation during conventional cardiopulmonary resuscitation. Our aim was to evaluate the impact of head elevation on survival, neurologic recovery and histopathologic outcome in addition to CARL in an animal model. Methods: After 20 min of ventricular fibrillation, 46 domestic pigs underwent CARL, including high, pulsatile extracorporeal blood flow, pH-stat acid-base management, priming with a colloid, mannitol and citrate, targeted oxygen, carbon dioxide and blood pressure management, rapid cooling and slow rewarming. N = 25 were head-up (HUP) during CARL, and N = 21 were supine (SUP). After weaning from ECC, the pigs were extubated and followed up in the animal care facility for up to seven days. Neuronal density was evaluated in neurohistopathology. Results: More animals in the HUP group survived and achieved a favorable neurological recovery, 21/25 (84%) versus 6/21 (29%) in the SUP group. Head positioning was an independent factor in neurologically favorable survival (p < 0.00012). Neurohistopathology showed no significant structural differences between HUP and SUP. Distinct, partly transient clinical neurologic deficits were blindness and ataxia. Conclusions: Head elevation during CARL after 20 min of cardiac arrest independently improved survival and neurologic outcome in pigs. Clinical follow-up revealed transient neurologic deficits potentially attributable to functions localized in the posterior perfusion area, whereas histopathologic findings did not show corresponding differences between the groups. A possible explanation of our findings may be venous congestion and edema as modifiable contributing factors of neurologic injury following prolonged cardiac arrest.

Minimally Invasive Surgery for Simple Congenital Heart Defects: Preserving Aesthetics without Jeopardizing Patient Safety.

Minimally invasive surgeries for pediatric patients have been proposed for decades, with different approaches in mind. Minimal right axillary thoracotomy (MRAT), proposed two decades ago, allows the preservation of patients' safety alongside faster aesthetic and functional recovery. The MRAT did not become widely adopted due to the prejudice that to follow a minimally invasive approach, safety and efficacy must be compromised. With this study, we aim to compare MRAT to the standard median sternotomy approach with a focus on safety and clinical outcomes. Between January 2017 and April 2021, 216 patients diagnosed with ASD, pAVSD, or PAPVD underwent surgical repair with different approaches in the same period. MRAT was used for 78 patients, and median sternotomy was used for 138 patients. In this last group, standard median sternotomy (SMS) was used for 116 patients, while a minimal skin incision (SMS mini) was used for 22 patients. There were no major complications overall nor in each specific approach. MRAT enabled the successful repair of simple heart defects, providing similar post-operative and cardiological recovery. MRAT does not compromise patients' safety and does not prolong the duration of surgery once the learning curve is overcome, which is generally after 15-20 consecutive operations.

Lutembacher's Syndrome Accompanied by Partial Anomalies of Pulmonary Veins in a 70-Year-Old Male: A Case of Congenital Heart Disease in the Elderly.

Lutembacher's syndrome is a rare disease defined as the combination of atrial septal defect and mitral stenosis, which relieves the progression of symptoms resulting from mitral stenosis. We present a case of a previously asymptomatic 70-year-old man having Lutembacher's syndrome with sinus venosus type of interatrial defect associated with partial anomalous pulmonary venous drainage. Our patient's only complaint was of mild exertional dyspnea, which started six months prior to referral. Clinical suspicion of the combination of defects arose during transthoracic echocardiography. The patient underwent transesophageal echocardiography and multi-slice computed tomography for defect confirmation. The combination of Lutembacher's syndrome with this complex deformity of pulmonary venous drainage has rarely been described. Such complex congenital defects with multifaceted physiological repercussions can go largely undiagnosed for the patients affected for most of their lifetimes. LEARNING POINTS: Despite the complexity of Lutembacher's syndrome, including the involvement of several deformities and pathological mechanisms of mitral stenosis, sinus venosus type of interatrial defects with partial anomalous return in the pulmonary veins, the multiplicity of mechanisms involved contribute to altered hemodynamics.Multiple intersecting mechanisms can further contribute to delaying congenital heart disease presentation. Congenital heart disease remains a plausible differential in the evaluation of elderly patients presenting with exertional dyspnea.Adult congenital heart defects can have very late onset for presentation, especially with physiological processes that paradoxically reduce the severity and progression of symptoms.

Increasing Venous Return Blood Flow to the Right Atrium Using the Party Balloon Inflation Maneuver.

The party balloon inflation maneuver increases intrathoracic pressure, decreases venous return, and after release enhances venous return to the right atrium more effectively than does the conventional Valsalva maneuver. Therefore, it shows potential for more effective detection of right-to-left shunts in patients with a patent foramen ovale. (Level of Difficulty: Intermediate.).