Coarctation of the frontal horns with acute distension of the trigones

A case of bilateral coarctation of the frontal horns with acute distension of the trigones is presented, and treatment with a bilateral ventriculoatrial shunt is discussed. Literature on the subject is considered, and a hypothesis is made concerning the pathogenesis of this very rare disorder.     

螺旋形心室肌带的研究进展

解剖学家从未停止对心脏结构的探索,但心室肌的结构犹如心脏解剖之中的"戈尔迪之结"无法解开.最近的文献对螺旋形心室肌带(HVMB)理论的讨论较多,该理论认为心室肌由一个起点为肺动脉根部,终点为主动脉根部的连续的肌肉带经过两个螺旋之后环绕而成.电兴奋沿着这条带的起点到终点的顺序收缩使心室肌的三维结构发生改变.该理论以全新的视角从整体、三维的角度理解心室肌结构及基于此基础上的心室肌功能,已经影响某些心脏疾病的诊断和治疗.然而,该理论在全世界范围内并未达成一致,其存在与否的争论较大,但是目前国内对此理论研究较少,本文综述了HVMB的解剖技术、生理功能、临床应用等方面,提出目前该理论存在的争论,预测其发展方向.     

Right ventricular failure after implantation of continuous flow left ventricular assist device: analysis of predictors and outcomes

Postoperative right ventricular failure is a serious complication for up to 50% of patients following LVAD insertion. Predicting RV failure is an important factor for patients as planned BiVAD support has been shown to correlate with better outcomes compared to delayed BiVAD to LVAD conversion. This retrospective study examined prospectively collected data for 101 patients implanted with an LVAD between 2003 and 2013, aiming to establish preoperative predictive factors for RVF post‐LVAD insertion, analyze outcomes, and validate existing RVF scoring systems. In our cohort, 63 patients (62.4%) developed RV failure and consequently demonstrated consistently poorer survival throughout the follow‐up period (log‐rank p = 0.01). Multivariable logistic regression identified two significant variables: cardiac index <2.2 preoperatively despite inotropic support (OR 4.6 [95%CI 1.8–11.8]; p = 0.001) and preoperative tricuspid regurgitation (OR 8.1 [95%CI 1.9–34]; p = 0.004). Patients who developed RV failure had more complicated postoperative courses including longer ICU stay (p < 0.001), higher incidence of transfusions (p = 0.03) and re‐intubation (p = 0.001), longer ventilation duration (p < 0.001), and higher incidence of returning to theater (p = 0.0008). This study found that previous validation models had only moderate correlation with our population emphasizing the need for prospective validation of these scores in the current era of continuous flow devices.     

Right ventricular end–systolic pressure–volume relation during propofol infusion

The effects of propofol on right ventricular function were studied in 11 ICU patients who needed sedation for acute respiratory failure or neurological diseases. Right ventricular function was studied using a thermodilution method at patients' bedside. Right ventricular ejection fraction (RVEF), cardiac output (CO), right ventricular end–diastolic volume (RVEDV), right ventricular end–systolic volume (RVESV), right ventricular end–systolic pressure (RVESP) and pulmonary capillary wedge pressure (PCWP) were obtained from a modified Swan–Ganz catheter. Calculation of right ventricular end–systolic pressure–volume relation (ESPVR) allowed to assess changes in right ventricular inotropic state. A baseline ESPVR was obtained before propofol infusion: RVESP = 0.21 RVESV + 2.4, r = 0.83, P < 0.0001. Then, patients were given an induction dose of 1 to 2.5 mg kg^-1 propofol over 1 min followed by a continuous infusion of 3 mg kg^-1 h^-1. During propofol infusion heart rate, mean arterial pressure, PCWP, CO, systemic vascular resistance and RVEF significantly decreased. No change in RVEDV and RVESV was observed. ESPVR was significantly altered with a dramatic decrease in the slope of the relation: RVESP = 0.12 RVESV + 6.9 ( P < 0.001 from baseline). Dobutamine was used in five patients with clinically significantly cardiac dysfunction and restored the slope of the ESPVR to the baseline value: RVESP = 0.22 RVESV + 6.3 (NS from baseline). In the study patients, propofol altered the inotropic state of the right ventricle.     

Surgery for ventricular tachycardia and left ventricular aneurysm provides arrhythmia control

Objectives. Report long-term freedom from ventricular tachycardia (VT), survival, and causes of death in patients with left ventricular aneurysm and VT, who underwent a combined procedure for VT and surgical ventricular restoration (SVR). Design. The primary outcome measures VT, survival, and cause of death, were ascertained by review of patients’ records, interrogation of implanted cardioverter-defibrillators and use of national registers. Results. Mean follow-up was 5.2 years. Overall survival was 62% at 5 years and 51% at 9 years. Freedom from spontaneous VT was 89%. In 32 patients who were non-inducible at postoperative testing, there was no occurrence of VT during a mean follow-up of 6.0 years. Causes of death were cardiac in 17 patients, and non-cardiac in 6 patients. No patient died from ventricular arrhythmia. Conclusions. Direct surgery for VT combined with SVR resulted in a very low risk of late recurrence of VT and good long-term survival. Implantation of a cardioverter-defibrillator can safely be withheld in patients who are non-inducible on postoperative programmed electrical stimulation.     

Surgery for Chronic Left Ventricular Aneurysm: Benefits and side effects

Seventy patients who underwent elective resection of symptomatic postinfarction apico-anterior left ventricular (LV) aneurysm with or without coronary revascularization are reviewed. The early (?30 day) mortality was 5.7%. Mural thrombosis occurred in 29 cases (41.4%), unrelated to the degree of preoperative LV impairment and predictable from preoperative LV angiography in only seven cases. The response to surgery comprised significant overall improvement of global LV ejection fraction (LVEF) during rest and of all variables in stress testing. This LVEF recovery correlated significantly with that of peak ejections rate, a variable of myocardial contractility. Contrastingly, right ventricular ejection fraction (RVEF) at rest decreased slightly but significantly without correlation to preoperative RVEF or LVEF. In comparisons between patients with congestive heart failure or angina at rest as dominant symptom, the former group showed greater depression of preoperative watt and LVEF but better postoperative recovery of these variables, while right ventricular deterioration was significant only in the latter. Postoperative recovery was best in patients with poor preoperative LV function (LVEF ? 20%), even when surgery comprised only aneurysmectomy in isolated but ungraftable LAD disease (5 cases). The observed RV deterioration may be ‘nonspecific', but it must be kept in mind as a side effect of the operation, as it detracts unpredictably from postoperative ventricular recovery. Patients with well preserved preoperative LVEF, small LV aneurysm and marginal expected postaneurysmectomy changes according to LaPlace's law are probably at risk, and surgery should then instead be directed towards preserving the remaining viable myocardium by direct revascularization.     

Clinical characteristics and outcomes of patients requiring prolonged inotropes after left ventricular assist device implantation

Limited data exist regarding patients with continuous-flow left ventricular assist device (LVAD) support who require long-term inotropes. Our primary objective was to evaluate the clinical characteristics and all-cause mortality of LVAD recipients with prolonged inotrope use (PIU). Secondary endpoints were to compare predictors of PIU, mortality, risk of late re-initiation of inotropes, time to gastrointestinal bleed (GIB), infection, and arrhythmias. Retrospective cohort study was conducted on adult patients with primary continuous-flow LVADs implanted from January 2008 to February 2017 and the patients were followed up through February 2018. We defined PIU as ≥14 days of inotrope support. Kaplan–Meier method, competing risk models and Cox proportional hazard models were used. Final analytic sample was 203 patients, 58% required PIU, and 10% were discharged on inotropes. There was no difference in preimplant characteristics. One-year survival rate was 87% if no PIU required, 74% if PIU required, and 72% if discharged on inotropes. PIU was associated with longer length of stay and higher incidence of GIB. We found no association between PIU and late re-initiation of inotropes, infection or arrhythmias. Adjusted hazard risk of death was increased in patients with PIU (HR = 1.66, P = .046), older age (HR = 1.28, P = .031), and higher creatinine levels (HR = 1.60, P = .007). Prolonged inotrope use is frequently encountered following LVAD implantation and is associated with adverse prognosis but remains a therapeutic option. Inability to wean inotropes prior to hospital discharge is a marker of patients at particularly higher risk of mortality following LVAD implantation.     

Catheter-directed neodymium:YAG laser injury of the left ventricle for arrhythmia ablation: dosimetry and hemodynamic, hematologic, and electrophysiologic effects

The study evaluated catheter-directed laser injury of the left ventricular myocardium in a canine model as a potential method for treatment of resistant ventricular tachycardia. The relationship between laser energy delivered, the laser delivery characteristics, and the lesion size was evaluated both in vitro and in vivo. The effect of laser injury on several hematologic and hemodynamic parameters was studied. Programmed electrical stimulation studies were performed to assess the proarrhythmia potential of laser injury of the myocardium. The results showed the depth and diameter of myocardial injury to be directly related to total laser energy applied. Both depth and diameter of injury were increased by multiple applications of laser energy to the same myocardial location. One-half to full thickness left ventricular injury was produced without perforation or embolization. Endocardial vaporization occurred only with laser powers higher than necessary to produce full-thickness injury. There was no sustained effect on the hemodynamic or hematologic variables studied, nor were proarrhythmia effects identified. The laser injury produced in these studies was of smaller magnitude than might be necessary for clinical arrhythmia ablation, and the lack of sustained hemodynamic effects and pro-arrhythmia potential needs to be verified in subsequent studies with larger laser lesions. The results support continued evaluation of catheter-directed laser injury of the myocardium as a potential method for elimination of life-threatening ventricular arrhythmias.     

In Vitro and In Vivo Testing of an Implantable Motor-Driven Left Ventricular Assist Device

Abstract: A totally implantable motor-driven left ventricular assist device (LVAD) has been developed and tested. The performance of this LVAD was tested in a mock circulatory system. This pump provided 8 L/min of output against a mean afterload of 120 mm Hg with a filling pressure of 20 mm Hg when the pump was operated in the fill/empty mode. The right and left pumps were tested in a mock loop. The right pump afterload was kept in the range from 23–32 mm Hg. With increase in the left pump afterload, the pump power output varied from 1.64 to 2.37 W. The instantaneous motor power input varied from 22.6 to 30.6 W with the total system efficiency ranging from 6.7 to 9.4%. To date, 4 in vivo studies have been conducted for up to 12 h. Two animals survived 12 and 10 h, respectively. Termination was due to bleeding in 1 animal, vent tube obstruction in 1, and respiratory failure in 2. All animals died of technical failure. Another experiment is to be undertaken, and a newly designed cannula is now being manufactured.     

A novel,highly discriminatory risk model predicting acute severe right ventricular failure in patients undergoing continuous‐flow left ventricular assist device implant

Various risk models with differing discriminatory power and predictive accuracy have been used to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) placement. There remains an unmet need for a contemporary risk score for continuous flow (CF)‐LVADs. We sought to independently validate and compare existing risk models in a large cohort of patients and develop a simple, yet highly predictive risk score for acute, severe RVF. Data from the Mechanical Circulatory Support Research Network (MCSRN) registry, consisting of patients who underwent CF‐LVAD implantation, were randomly divided into equal‐sized derivation and validation samples. RVF scores were calculated for the entire sample, and the need for a right ventricular assist device (RVAD) was the primary endpoint. Candidate predictors from the derivation sample were subjected to backward stepwise logistic regression until the model with lowest Akaike information criterion value was identified. A risk score was developed based on the identified variables and their respective regression coefficients. Between May 2004 and September 2014, 734 patients underwent implantation of CF‐LVADs [HeartMate II LVAD, 76% (n = 560), HeartWare HVAD, 24% (n = 174)]. A RVAD was required in 4.5% (n = 33) of the patients [Derivation cohort, n = 15 (4.3%); Validation cohort, n = 18 (5.2%); P = 0.68)]. 19.5% of the patients (n = 143) were female, median age at implant was 59 years (IQR, 49.4–65.3), and median INTERMACS profile was 3 (IQR, 2–3). RVAD was required in 4.5% (n = 33) of the patients. Correlates of acute, severe RVF in the final model included heart rate, albumin, BUN, WBC, cardiac index, and TR severity. Areas under the curves (AUC) for most commonly used risk predictors ranged from 0.61 to 0.78. The AUC for the new model was 0.89 in the derivation and 0.92 in the validation cohort. Proposed risk model provides very high discriminatory power predicting acute severe right ventricular failure and can be reliably applied to patients undergoing placement of contemporary continuous flow left ventricular assist devices.     

Assessed value of high-sensitivity cardiac troponin T for cardiovascular disease among CKD patients

Objective To analyze the relationship between serum high-sensitivity cardiac troponin T (hs-cTnT) and cardiovascular disease (CVD) among non-dialysis chronic kidney disease (CKD) patients, and to further explore its value of evaluating and predicting CVD in this population. Methods Five hundred and fifty-seven non-dialysis CKD patients were involved in this cross-sectional study. The relationship between serum hs-cTnT and CVD was analyzed using comparison between groups and regression analysis, and its value on assessing cardiac structure and function was evaluated by ROC curves. Results Median level of hs-cTnT was 13 (7–29) ng/L, with 1.7% undetectable, 46.4% greater than 99th percentile of the general population. Multivariate analysis suggested that compared with the lowest quartile of hs-cTnT, the highest quartile was approximately six times as likely to develop into LVH (OR, 6.515; 95% CI, 3.478–12.206, p?<?0.05) and 18 times as likely to progress to left ventricular diastolic dysfunction(OR, 18.741; 95% CI, 2.422–145.017, p?<?0.05). And Ln cTnT level had a more modest association with LVEF (OR, ?1.117; 95% CI, ?5.839 to ?0.594; p?<?0.05). When evaluated as a screening test, the area under the curve of ROC curves for hs-cTnT was 0.718, 0.788 and 0.736, respectively (p?<?0.05). With a specificity of 90% as a diagnostic criterion, the value of hs-cTnT to evaluate LVH, LVEF?Conclusions In CKD non-dialysis population, hs-cTnT and NT-proBNP were valuable for evaluating LVH, left ventricular systolic dysfunction and left ventricular diastolic dysfunction.     

Experimental Assessment of Right Ventricular Function in Normal Pigs with a Left Ventricular Assist Device

Abstract: Right ventricular (RV) failure during the use of a left ventricular assist device (LVAD) is the leading cause of death in circulatory support patients. Previous work, both experimentally and clinically, has shown the difficulties in predicting the behavior of the right ventricle at the start of LVAD. An experimental study has been designed to evaluate RV functional changes during LVAD and its relation to preload changes. The model used adult mongrel pigs (n = 10). Right ventricular functional parameters were measured with a thermodilution RV ejection fraction catheter. The left ventricle was supported by a Nippon Zeon blood pump. Two groups were studied, the first one was the LVAD–off group (n = 5) and the other was the LVAD–on group (n = 5) which was supported by LVAD at maximum flow. Change of cardiac output, mean pulmonary artery pressure (PAP), RV stroke work, and RV ejection fraction in both groups were not significantly different. However, the relationship between right ventricular end–diastolic pressure (RV–EDP) and right ventricular stroke volume (RVSV) was significantly changed at a high level of RV–EDP. When RV–EDP was over 6. 5 mm Hg in the LVAD–off group, RVSV decreased to 52. 3 ± 11. 5 ml while in the LVAD–on group, RVSV increased to 97. 2 ± 22. 0 ml. The change in PAP in the LVAD–on group was lower than in the LVAD–off group. We conclude that, at the volume overload state, LVAD can reduce the afterload of the right ventricle and maintain Frank–Starling's effect, thus having a beneficial effect on right ventricular performance.     

右心室肥厚和衰竭心肌细胞Ca 2+稳态变化的研究进展

右心室肥厚（right ventricular hypertrophy, RVH）和右心室衰竭（right ventricular failure, RVF）是具有致命性的恶性心脏疾病,肺动脉高压（pulmonary arterial hypertension, PAH）是主要的致病因素。大量研究已经发现,Ca ...     

Development of the NEDO implantable ventricular assist device with Gyro centrifugal pump

The Gyro centrifugal pump, PI (permanently implantable) series, is being developed as a totally implantable artificial heart. Our final goal is to establish a "functional TAH," a totally implantable biventricular assist system (BiVAS) with centrifugal pumps. A plastic prototype pump, Gyro PI 601, was evaluated through in vitro and in vivo studies as a single ventricular assist device (VAD). Based upon these results, the pump head material was converted to a titanium alloy, and the actuator was modified. These titanium Gyro pumps, PI 700 series, also were subjected to in vitro and in vivo studies. The Gyro PI 601 and PI 700 series have the same inner dimensions and characteristics, such as the eccentric inlet port, double pivot bearing system, secondary vane, and magnet coupling system; however, the material of the PI 700 is different from the PI 601. The Gyro PI series is driven by the Vienna DC brushless motor actuator. The inlet cannula of the right ventricular assist system (RVAS) specially made for this system consists of 2 parts: a hat-shaped silicone tip biolized with gelatin and an angled wire reinforced tube made of polyvinylchloride. The pump-actuator package was implanted into 8 calves in the preperitoneal space, bypassing from the left ventricle apex to the descending aorta for the left ventricular assist system (LVAS) and bypassing the right ventricle to the main pulmonary artery for the RVAS. According to the PI 601 feasibility protocol, 2 LVAS cases were terminated after 2 weeks, and 1 LVAS case and 1 RVAS were terminated after 1 month. The PI 700 series was implanted into 4 cases: 3 LVAS cases survived for a long term, 2 of them over 200 days (72-283 days), and 1 RVAS case survived for 1 month and was terminated according to the protocol for a short-term antithrombogenic screening and system feasibility study. Regarding power consumption, the plastic pump cases demonstrated from 6.2 to 12.1 W as LVAS and 7.3 W as RVAS, the titanium pump cases showed from 10.4 to 14.2 W as LVAS and 15.8 W as RVAS. All cases exhibited low hemolysis. The renal function and the liver function were maintained normally in all cases throughout these experimental periods. In the 2 RVAS cases, pulmonary function was normally maintained. No calves demonstrated thromboembolic signs or symptoms throughout the experiments except Case 1 with the plastic pump. However, in the plastic pump cases, bilateral renal infarction was suspected in 2 cases during necropsy whereas no abnormal findings were revealed in the titanium pump cases. There were also no blood clots inside the PI 700 series. As for the 601, the explanted pumps demonstrated slight thrombus formations at the top and bottom pivots except in 1 case. The Gyro PI series, especially the PI 700 series, demonstrated superior performance, biocompatibility, antithrombogenicity and low hemolysis. Also, the durability of the actuator was demonstrated. Based on these results, this titanium centrifugal pump is suitable as an implantable LVAS and RVAS. It is likely that the Gyro PI series is a feasible component of the BiVAS functional TAH.     

Left ventricular diastolic function in patients on maintenance haemodialysis

SUMMARY: The aim of this study was to elucidate the differences in left ventricular (LV) diastolic function between patients on maintenance haemodialysis (HD) with LV hypertrophy (LVH) and those with LVH from other causes. Twenty HD patients (HD group), 11 patients with hypertensive heart disease (HHD group), 11 with hypertrophic cardiomyopathy (HCM group) and 11 age-matched healthy individuals (N group) were examined using echocardiography. Compared with the HCM group, the HD and HHD groups had smaller total LV wall thickness and left atrial dimension, a higher ratio of LV end-diastolic dimension to LV posterior wall thickness, a shorter isovolumic relaxation time and a higher ratio of peak flow velocity of early to late LV fillings (E/A). There was a correlation between LV mass index or E/A and systolic blood pressure. These results indicate that HD patients have an LV diastolic dysfunction similar to that observed in HHD patients but which is less severe than that found in HCM patients. It seems reasonable to control hypertension in HD patients in order to favourably influence LV diastolic function.     

Right ventricular disarticulation. An 18-year single centre experience

Objective: Right ventricular disarticulation (RVD) is an accepted procedure in the treatment of ventricular tachycardia of right ventricular origin. We set out to review the long-term outcomes with RVD at our institution for patients with arrhythmogenic right ventricular dysplasia (ARVD) or refractory tachycardia. A renewed interest in this operation has come about in patients unable to tolerate implantable cardioverter defibrillators. Methods: Seventeen patients had RVD carried out between 1985 and 2003. There were 15 males and 2 females. The age range was 14–72 (median: 34). Six patients had partial RVD and 11 a complete RVD. ARVD was confirmed in 15 patients at histology. Biventricular pacing was used post-operatively in the two most recent patients. Results: The follow-up was complete in 94% (16/17). The median follow-up was 13 years (0–18). The overall hospital mortality was 6% (1/17). Over the follow-up period there were three deaths 9, 11 and 17 years post-surgery. Heart transplantation due to biventricular failure was required in two patients. In the group followed up for more than 10 years the over all event free survival at 10 years was 77% (3/13). Conclusions: In cases of refractory ventricular tachycardia, where multiple antiarrhythmic medication, repeated catheter ablation and ICD insertion are unsuccessful at symptom control, RVD is an excellent antiarrhythmic procedure. In the long term, signs of biventricular failure present, possibly, dependent on the natural history of ARVD. The long-term effect of biventricular pacing on the disarticulated right ventricle is yet to be defined.