Minimally Invasive Mitral Valve Repair: From Total Endoscopic To Closed-Chest Robotic.

Minimally invasive cardiac surgery has evolved over the past few decades, thanks to advancements in technology and surgical techniques. These advancements have allowed surgeons to perform cardiac interventions through small incisions, reducing surgical trauma and improving patient outcomes1. However, despite these advancements, thoracoscopic mitral repair has not been widely adopted by the cardiac surgery community, possibly due to the lack of familiarity with video-assisted procedures1. Over the years, various minimally invasive mitral valve surgery (MIMVS) techniques have been developed to achieve comparable or better results while minimizing surgical trauma. These techniques have evolved from direct-vision procedures performed through a right thoracotomy with a rib retractor to video-directed approaches using long-shafted instruments1. Robotic surgery, introduced in the late 90s, has also played a significant role in mitral valve repair. The da Vinci system, the only robotic platform currently used for cardiac surgery, provides surgeons with enhanced dexterity and high-definition 3D visualization, allowing for precise and accurate procedure2, and is now the preferred approach for mitral repair in many programs3. The first mitral repair using the da Vinci system was performed in Europe by Carpentier and Mohr in 1998, followed by the first mitral replacement by Chitwood in the USA in 20002-4. The advantages of robotic technology allow surgeons to perform complex repair techniques such as papillary muscle repositioning and sliding leaflet plasty4. Studies have shown that robotic mitral surgery results in shorter ICU and hospital stays, better quality of life postoperatively, and improved cosmesis compared to conventional surgery5,6. In our experience, we have also observed significant benefits with robotic surgery, including reduced blood loss and the need for transfusions. This can be attributed to the closed-chest technique, which eliminates the need for a thoracotomy and rib retractor, reducing the risk of bleeding associated with these approaches7. In this article, we will compare the surgical steps of endoscopic and robotic mitral valve repair, providing detailed information on patient selection, operative techniques, and the requirements for building a successful program. By understanding the advantages and challenges of both approaches, surgeons can make informed decisions and provide the best possible care for their patients. Combined ablation and multivalvular procedures are mostly performed in few centers by minimally invasive techniques.

ISCHEMIC MITRAL REGURGITATION - TO REPAIR OR REPLACE? LOOKING BEYOND THE VALVE.

INTRODUCTION: Ischemic mitral regurgitation (IMR) is a frequent and serious complication of coronary artery disease, associated with considerable patient increased mortality and morbidity. While the benefits of optimal medical therapy and surgical revascularization, when indicated, are uncontested in moderate to severe cases, the ideal surgical approach to the valve, if any, is yet to be established. Mitral valve repair has established benefits over replacement in primary mitral regurgitation, but its superiority in the treatment of functional regurgitation has not been replicated. Differing outcomes likely stem from the distinct IMR pathophysiology. Unlike its degenerative counterparts, IMR does not derive from direct damage to the valve leaflets, but rather from dysfunction of its sub-valvular apparatus and the left ventricular wall, in the context of acute or chronic ischaemia. Echocardiographic data points to remodelling of the left ventricle, with subsequent papillary muscle displacement, increased leaflet tethering and inefficient coaptation, as the main responsible mechanism for ischemic mitral regurgitation. Neither mitral valve repair nor replacement directly address these issues, with the appearance of the first randomized trials supporting replacement as the more durable option. However, new subvalvular procedures are improving the stability of repair techniques and the debate is long from settled. The purpose of this review is to analyse the currently available data, couple it with our understanding of IMR's pathophysiology and compare the different outcomes for mitral valve repair and  replacement.

Arterial Stiffness Changes in Severe Aortic Stenosis Patients Submitted to Valve Replacement Surgery. / Alterações da Rigidez Arterial em Pacientes com Estenose Aórtica Grave Submetidos à Cirurgia de Troca Valvar.

BACKGROUND: Little is known about the impact of severe aortic stenosis (AS) in aortic stiffness and if there is any change after removing AS barrier with aortic valve replacement (AVR) surgery. OBJECTIVE: To estimate carotid-femoral pulse wave velocity (PWV) changes after AVR surgery and to define PWV predictors in severe AS patients. METHODS: Single-center retrospective cohort, including patients with severe AS who underwent AVR surgery with bioprostheses, between February 2017 and January 2019 and performed PWV measurements (Complior®) before and after the procedure (2±1 months). Before and after AVR, PWV values were compared through paired tests. The associations of PWV with clinical data were studied and linear regression models were applied to estimate pre and postoperative PWV independent predictors. The significance level was set at 5%. RESULTS: We included 150 patients in the sample, with mean age of 72±8 years, and 51% being males. We found a statistically significant increase in PWV values after surgery (9.0±2.1 m/s vs. 9.9±2.2, p<0.001, before and after AVR, respectively) and an inverse association with AS severity variables. In the linear regression model, age and systolic blood pressure (SBP) were established as independent predictors of higher pre- and postoperative PWV, while higher mean valvular gradient emerged as a determinant of lower pre-AVR PWV. CONCLUSION: We documented an inverse correlation of arterial stiffness with the severity of AS in patients with AS, and a significant increase in PWV values after AVR surgery. Advanced age and higher SBP were associated with higher PWV values, although arterial function measurements were within the normal range. (Arq Bras Cardiol. 2021; 116(3):475-482).

FUNDAMENTO: Pouco se sabe sobre o impacto da estenose aórtica (EA) grave na rigidez aórtica e se ocorre alguma alteração após a remoção da barreira de EA com a cirurgia de substituição da válvula aórtica (SVA). OBJETIVO: Estimar as mudanças na velocidade de onda de pulso carotídeo-femoral (VOP) após a cirurgia de SVA e definir os preditores de VOP alta em pacientes com EA grave. MÉTODOS: Estudo de coorte retrospectivo unicêntrico, incluindo pacientes com EA grave submetidos à cirurgia de SVA com bioprótese, entre fevereiro de 2017 e janeiro de 2019, e medições da VOP (Complior®) antes e depois do procedimento (2±1 meses). Antes e depois da SVA, os valores da VOP foram comparados por meio de testes pareados. foram analisadas as associações de VOP com dados clínicos, bem como aplicados modelos de regressão linear multivariada para estimar os preditores independentes da VOP pré- e pós-operatória. O nível de significância foi estabelecido em 5%. RESULTADOS: Foram incluídos na amostra 150 pacientes, com média de idade de 72±8 anos, sendo 51% deles do sexo masculino. Identificamos um aumento estatisticamente significativo nos valores de VOP após a cirurgia (9,0 ± 2,1 m/s vs. 9,9 ± 2,2, p<0,001, antes e depois da SVA, respectivamente) e uma associação inversa com as variáveis de gravidade da EA. No modelo de regressão linear multivariada, idade e pressão arterial sistólica (PAS) foram estabelecidas como preditores independentes da VOP pré- e pós-operatória mais alta, enquanto o gradiente valvar médio mais alto foi considerado um determinante da VOP pré-SVA mais baixa. CONCLUSÃO: Identificamos uma correlação inversa da rigidez arterial com a gravidade da EA em pacientes acometidos, e um aumento significativo nos valores da VOP após a cirurgia de SVA. Idade avançada e PAS elevada foram associadas a valores mais altos da VOP, embora as medidas de função arterial estivessem dentro da normalidade. (Arq Bras Cardiol. 2021; 116(3):475-476).

Alterações da Rigidez Arterial em Pacientes com Estenose Aórtica Grave Submetidos à Cirurgia de Troca Valvar / Arterial Stiffness Changes in Severe Aortic Stenosis Patients Submitted to Valve Replacement Surgery

Resumo Fundamento: Pouco se sabe sobre o impacto da estenose aórtica (EA) grave na rigidez aórtica e se ocorre alguma alteração após a remoção da barreira de EA com a cirurgia de substituição da válvula aórtica (SVA). Objetivo: Estimar as mudanças na velocidade de onda de pulso carotídeo-femoral (VOP) após a cirurgia de SVA e definir os preditores de VOP alta em pacientes com EA grave. Métodos: Estudo de coorte retrospectivo unicêntrico, incluindo pacientes com EA grave submetidos à cirurgia de SVA com bioprótese, entre fevereiro de 2017 e janeiro de 2019, e medições da VOP (Complior®) antes e depois do procedimento (2±1 meses). Antes e depois da SVA, os valores da VOP foram comparados por meio de testes pareados. foram analisadas as associações de VOP com dados clínicos, bem como aplicados modelos de regressão linear multivariada para estimar os preditores independentes da VOP pré- e pós-operatória. O nível de significância foi estabelecido em 5%. Resultados: Foram incluídos na amostra 150 pacientes, com média de idade de 72±8 anos, sendo 51% deles do sexo masculino. Identificamos um aumento estatisticamente significativo nos valores de VOP após a cirurgia (9,0 ± 2,1 m/s vs. 9,9 ± 2,2, p<0,001, antes e depois da SVA, respectivamente) e uma associação inversa com as variáveis de gravidade da EA. No modelo de regressão linear multivariada, idade e pressão arterial sistólica (PAS) foram estabelecidas como preditores independentes da VOP pré- e pós-operatória mais alta, enquanto o gradiente valvar médio mais alto foi considerado um determinante da VOP pré-SVA mais baixa. Conclusão: Identificamos uma correlação inversa da rigidez arterial com a gravidade da EA em pacientes acometidos, e um aumento significativo nos valores da VOP após a cirurgia de SVA. Idade avançada e PAS elevada foram associadas a valores mais altos da VOP, embora as medidas de função arterial estivessem dentro da normalidade. (Arq Bras Cardiol. 2021; 116(3):475-476)

Abstract Background: Little is known about the impact of severe aortic stenosis (AS) in aortic stiffness and if there is any change after removing AS barrier with aortic valve replacement (AVR) surgery. Objective: To estimate carotid-femoral pulse wave velocity (PWV) changes after AVR surgery and to define PWV predictors in severe AS patients. Methods: Single-center retrospective cohort, including patients with severe AS who underwent AVR surgery with bioprostheses, between February 2017 and January 2019 and performed PWV measurements (Complior®) before and after the procedure (2±1 months). Before and after AVR, PWV values were compared through paired tests. The associations of PWV with clinical data were studied and linear regression models were applied to estimate pre and postoperative PWV independent predictors. The significance level was set at 5%. Results: We included 150 patients in the sample, with mean age of 72±8 years, and 51% being males. We found a statistically significant increase in PWV values after surgery (9.0±2.1 m/s vs. 9.9±2.2, p<0.001, before and after AVR, respectively) and an inverse association with AS severity variables. In the linear regression model, age and systolic blood pressure (SBP) were established as independent predictors of higher pre- and postoperative PWV, while higher mean valvular gradient emerged as a determinant of lower pre-AVR PWV. Conclusion: We documented an inverse correlation of arterial stiffness with the severity of AS in patients with AS, and a significant increase in PWV values after AVR surgery. Advanced age and higher SBP were associated with higher PWV values, although arterial function measurements were within the normal range. (Arq Bras Cardiol. 2021; 116(3):475-482)

Freedom Solo® versus Trifecta® bioprostheses: clinical and haemodynamic evaluation after propensity score matching.

OBJECTIVES: The goal of this study was to compare the stentless Freedom Solo® (FS) and the stented Trifecta® (TF) aortic bioprostheses with regard to haemodynamic profile, left ventricular mass regression and early and late postoperative outcomes and survival. METHODS: A longitudinal cohort study of consecutive patients undergoing aortic valve replacement (2009-16) with either the FS or TF at 1 centre was performed. Local databases and national records were queried. Prosthesis haemodynamics and left ventricular dimensions were obtained from postoperative echocardiograms. After propensity score matching (21 covariates), the Kaplan-Meier and competing risk analyses were performed for survival and the combined outcome of structural valve deterioration and endocarditis, respectively. Haemodynamics and mass regression were assessed by a mixed-effects model including propensity score as a covariate. RESULTS: From a total sample of 397 patients with the FS and 525 TF bioprostheses with a median follow-up time of 4.0 (2.2-6.0) and 2.4 (1.4-3.7) years, respectively, a matched sample of 329 pairs was obtained. Matched groups showed no differences in survival (hazard ratio = 1.04, 95% confidence interval = 0.69-1.56) or cumulative hazards of combined outcome (subdistribution hazard ratio = 0.54, 95% confidence interval = 0.21-1.39). Although the TF showed an improved haemodynamic profile, no difference was found in mass regression. Patients with TF bioprostheses had higher rates of prolonged mechanical ventilation, whereas patients with the FS bioprosthesis showed higher rates of thrombocytopenia. CONCLUSIONS: The TF showed an improved haemodynamic profile compared to the FS, but this did not translate into further reverse remodelling. Postoperative outcomes and survival rates were comparable for both bioprostheses. Long-term follow-up is needed for comparisons with classical bioprosthesis models.

An Unusual Case of Tricuspid Stenosis.

Tricuspid stenosis is an uncommon valvular abnormality commonly associated with other valvular lesions. Ebstein's anomaly is a rare congenital heart malformation characterized primarily by abnormalities of the tricuspid valve and right ventricle. Endomyocardial fibrosis is a restrictive cardiomyopathy observed in tropical and subtropical regions. It may cause right ventricular distortion with apparent apical displacement of the tricuspid valve, mimicking Ebstein's anomaly. Eosinophilia is the most commonly cited aetiological link in endomyocardial fibrosis. Here we report the case of 42-year-old male patient who presented with heart failure and severe tricuspid stenosis where a diagnosis of hypereosinophilic syndrome was also established. This case represented a diagnostic challenge in the search for the definitive cause of the tricuspid stenosis. LEARNING POINTS: Ebstein's anomaly is a rare congenital heart malformation characterized primarily by abnormalities of the tricuspid valve and right ventricle. The tricuspid valve is usually incompetent, and very rarely stenotic.Hypereosinophilic syndromes can be associated with heart damage. The fibrotic stage of eosinophil-mediated heart damage is characterized by altered cardiac function due to either compromise/entrapment of the cordae tendineae and/or restrictive cardiomyopathy.Endomyocardial fibrosis is a restrictive cardiomyopathy observed in tropical and subtropical regions that may be indistinguishable from the Loeffler's endocarditis observed in temperate climates. It may cause right ventricle distortion and apical displacement of the tricuspid valve, mimicking Ebstein's anomaly.

Pericardial mesothelioma presenting as a suspected ST-elevation myocardial infarction.

Primary cardiac and pericardial tumors are rare entities with an autopsy frequency of 0.001-0.03%. Metastases to the heart and pericardium are much more common than primary tumors. Malignant pericardial mesotheliomas account for up to 50% of primary pericardial tumors. We report the case of a 75-year-old woman with hypertension, dyslipidemia and atrial fibrillation who went to the emergency department due to nonspecific thoracic discomfort of over six hours duration associated with syncope. Physical examination revealed a low-amplitude arrhythmic pulse, no heart murmurs and no signs of pulmonary congestion. The ECG revealed atrial fibrillation with ST-segment elevation in V2-V6, I and aVL. The patient was transferred for emergent coronary angiography, which revealed a long stenosis in the mid-distal portion of the left anterior descending artery. The echocardiogram showed a large pericardial effusion with diffuse thickening of the myocardium. Due to worsening hemodynamics, cardiac rupture was suspected and the patient underwent urgent sternotomy and pericardiotomy with drainage of a large quantity of hematic fluid. The surgeons then identified a large, unresectable tumor occupying the distal half of the anterior portion of the heart. This is, to our knowledge, the first case report of primary pericardial mesothelioma presenting with suspected ST-elevation myocardial infarction. In this case, direct observation of the tumor led to biopsy and the final diagnosis. These are highly malignant tumors and when diagnosed are usually already at an advanced stage.

[Atrioventricular septal defect in an adult patient: There are 'clefts' and clefts]. / Defeito do septo auriculoventricular num doente adulto. Há «fendas¼ e fendas.

In this report, we present the case of an adult male with severe mitral regurgitation due to an atrioventricular septal defect. Anatomical assessment by two- and three-dimensional transesophageal echocardiography was essential for detailed morphological characterization and surgical planning. The different features of a 'cleft' in an atrioventricular septal defect compared to an anterior leaflet cleft in an otherwise normal mitral valve are here discussed.

The TRIBECA study: (TRI)fecta (B)ioprosthesis (E)valuation versus (C)arpentier Magna-Ease in (A)ortic position.

OBJECTIVE: To determine whether the Trifecta bioprosthetic aortic valve produces postoperative haemodynamic results comparable with or better than those of the Magna Ease aortic valve bioprosthesis. METHODS: We retrospectively reviewed the medical records of patients who had undergone aortic valve replacement with Trifecta or Magna Ease prostheses at eight European institutions between January 2011 and May 2013, and analysed early postoperative haemodynamic performance by means of echocardiography. RESULTS: A total of 791 patients underwent aortic valve replacement (469 Magna Ease, 322 Trifecta). Haemodynamic variables were evaluated on discharge and during the follow-up (minimum 6 months, maximum 12 months). The mean gradient and the indexed effective orifice area (IEOA) were as follows: 10 mmHg [interquartile range (IQR): 8-13] and 1.10 cm(2)/m(2) (IQR: 0.95-1.27) for Trifecta; 16 mmHg (IQR: 11-22) and 0.96 cm(2)/m(2) (IQR: 0.77-1.13) for Magna Ease (P < 0.001). These significant differences were maintained across all valve sizes. Similar statistically significant differences were found when patients were matched and/or stratified for preoperative characteristics: body-surface area, ejection fraction, mean gradients and valve size. Severe prosthesis-patient mismatch (IEOA: <0.65 cm(2)/m(2)) was detected in 2 patients (0.6%) with Trifecta and 40 patients (8.5%) with Magna Ease (P < 0.001). CONCLUSIONS: The haemodynamic performance of the Trifecta bioprosthesis was superior to that of the Magna Ease valve across all conventional prosthesis sizes, with almost no incidence of severe patient-prosthesis mismatch. The long-term follow-up is needed to determine whether these significant haemodynamic differences will persist, and influence clinical outcomes.

[Do diabetic patients benefit from bilateral internal mammary artery?] / O Benefício na Sobrevida da Dupla Artéria Torácica Interna Prevalece nos Pacientes com Diabetes?

INTRODUCTION: Bilateral internal mammary artery (BIMA) grafting has been associated with increased long term survival when compared to single IMA, but its benefit on diabetic patients remains controversial. AIMS: To compare long-term survival following BIMA versus single internal mammary artery (SIMA) grafting between diabetic and non-diabetic patients. METHODS: We retrospectively reviewed all the patients who underwent isolated CABG and received two or more grafts with at least one IMA graft between 2004 and 2013. Mean follow-up was 4 years and maximum 10. Kaplan-Meier analysis was used to compare long-term survival between BIMA and SIMA in both groups (diabetic vs. non-diabetic). Propensity score matching was used to adjust for treatment selection bias. RESULTS: 1259 out of 3045 eligible patients were diabetic. BIMA was associated with better long-term survival than SIMA on unadjusted analysis in both groups (cumulative survival of 87% vs. 70% in diabetic patients and 89% vs. 79% in non-diabetic patients, respectively). After propensity score matching, BIMA was associated with increased long-term survival in the non-diabetic cohort (n=1042, HR: 0.570 CI95%: 0.342-0.950), but there was no statistically significant difference in the diabetic cohort (n=850, HR: 0.774 CI95% 0.447-1.339). In-hospital mortality and sternal wound infection were low in matching cohorts irrespectively of the number of IMA grafts or diabetes status. CONCLUSIONS: BIMA grafting appears to be safe for diabetic patients, despite the apparent lack of significant survival advantage.

[Bilateral Internal Mammary Artery Versus Single Internal Mammary Artery in Myocardial Revascularization Surgery. Propensity Score - Adjusted Survival Analysis]. / Dupla Artéria Torácica Interna Versus Artéria Torácica Interna Única na Cirurgia de Revascularização do Miocárdio : Análise Ajustada de Sobrevida com Emparelhamento por Propensy Score.

BACKGROUND: Although arterial grafts are superior to venous grafts in terms of long-term patency, single internal mammary artery (SIMA) is still the preferred strategy in most cardiac surgical centres. Our main aim was to compare long- -term survival between BIMA and SIMA at our own tertiary care centre. METHODS: Retrospective cohort including patients referred to Centro Hospitalar São João (CHSJ), from 2004 to 2011, who underwent isolated CABG and received two or more bypass with at least 1 IMA graft. Kaplan-Meier, Cox regression and propensity score matching 2:1 were used to compare long-term survival between BIMA and SIMA. RESULTS: BIMA was performed in 696 (29.3%) out of 2329 eligible procedures. Mean follow-up time was 5.1 years (2-9.9 years). All-cause mortality was superior in patients with only one internal mammary artery - cumulative survival of 75% for SIMA vs 88% for BIMA. Because of discrepancy between groups regarding preoperative and surgical characteristics, we ran a propensity score matching which revealed BIMA as an independent predictor of survival (n=1510, 40.3% BIMA, HR: 0.648, 95% CI: 0.452-0.927). CONCLUSION: BIMA is associated with significantly better long-term survival than SIMA in CABG. A higher sample size might clarify BIMA advantages, discriminating specific groups that might profit the most with this approach.

Angiotensin-(1-7) modulates angiotensin II-induced vasoconstriction in human mammary artery.

PURPOSE: The renin-angiotensin system plays a key role in cardiovascular pathophysiology and one of its members, angiotensin-(1-7) (ANG-(1-7)), is now recognized as a peptide with the ability to counter-regulate angiotensin II (ANGII) effects. We sought to investigate ANG-(1-7) actions in human vessels, particularly its effect on ANGII-induced vasoconstriction in human mammary arteries (HMA). METHODS: Samples of HMA from patients submitted to coronary revascularization (22 patients, mean age 67 years) were cut into small rings, mounted in a myograph bath system, normalized and allowed to contract and dilate isometrically. In baseline experiments, the rings were incubated with ANG-(1-7) or vehicle, followed by increasing concentrations of ANGII. This protocol was repeated in the presence of A-779, PD123177, losartan and after mechanical endothelium removal. Western blot analysis and immunofluorescence were also performed in order to verify the presence of Mas receptor in HMA. RESULTS: ANG-(1-7) significantly attenuated ANGII-induced contraction, producing a maximal inhibition of approximately 65.2%. This effect was not abolished by A-779, PD123177 or endothelium removal. In the presence of losartan, ANGII response was attenuated and no differences were observed between ANG-(1-7) and vehicle treated rings. Finally, we observed, for the first time, that the Mas receptor is expressed in HMA endothelium. CONCLUSIONS: ANG-(1-7) significantly attenuates ANGII-induced vasoconstriction and, although the Mas receptor is expressed in HMA, this effect seems to be independent of its activation. Additionally, AT2 receptor and endothelium are not involved in this mechanism, which suggests a direct effect on smooth muscle cells.

Load independent impairment of reverse remodeling after valve replacement in hypertensive aortic stenosis patients.

BACKGROUND: We evaluated the impact of hypertension on the left ventricular mass regression in aortic stenosis after aortic valve replacement. METHODS: We prospectively studied 135 patients with severe aortic stenosis at baseline and 1 year after surgery. In 32 patients we analyzed myocardial gene expression of collagen types I and III, connective tissue growth factor, transforming growth factor-ß1, metalloproteinase-2 and its tissue inhibitor and compared its levels vs controls. RESULTS: Seventy-six patients (56.3%) had a history of hypertension. Hypertensive patients were older, had higher Euroscore-II and NYHA class, with no differences in stenosis severity. At 1 year follow-up there was a median decrease of mass index of 14.2% (P25-75: -4.3%-30.4%; p<0.001). Mass regression was significantly higher in patients without hypertension, with a median decrease of 25.9% (P25-75: 12.0%-38.7%) vs 5.4% (P25-75: -12.5%-20.1%; p=0.001), despite similar increase in effective orifice area and no differences in valvuloarterial impedance. After 1 year, higher baseline left ventricular mass index (p=0.005) and the absence of hypertension (p=0.002) or diabetes (p=0.041) were the only independent predictors of mass regression higher than the median. Comparing with controls, aortic stenosis patients had an increased expression of collagen types I and III, but only hypertensive patients had higher relative expression of collagen type I vs III. In hypertensive patients TIMP2 expression was up-regulated and correlated with higher baseline left ventricular mass index (r=0.61; p=0.020). CONCLUSIONS: In aortic stenosis, hypertension impairs mass regression one year after valve replacement, independently of total afterload. Differences in the expression of extracellular matrix remodeling genes might contribute to this finding.

Ischemic rupture of the anterolateral papillary muscle.

We describe the case of a 59-year-old man who presented with chest pain and ST-segment elevation in the inferior leads, R>S in V1 and ST depression in the anterior leads due to proximal occlusion of the first obtuse marginal. Primary coronary angioplasty and stenting of this artery were performed. Twelve hours later the patient became hemodynamically unstable and severe mitral regurgitation due to rupture of one of the heads of the anterolateral papillary muscle was diagnosed. Emergency surgery was performed (papillary muscle head reimplantation, mitral annuloplasty with a rigid ring, tricuspid annuloplasty and coronary artery bypass grafting). On surgical inspection, it was observed that the detached muscle head had become trapped in the left ventricle by a secondary cord attached to the other head. This case is unusual in presenting two uncommon features of ischemic papillary muscle: rupture of the anterolateral muscle in myocardial infarction involving the inferoposterior walls, and the fact that the ruptured muscle head did not prolapse because it had become trapped in the left ventricle by secondary cord attachment.

Intraventricular pressure gradients throughout the cardiac cycle: effects of ischaemia and modulation by afterload.

The aim of the present study was to characterize the intraventricular pressure gradients (IVPGs) througout the cardiac cycle, to correlate them with myocardial segmental asynchrony and to evaluate the effects of ischaemia and modulation by afterload. Open-chest anaesthetized rabbits (n = 6) were instrumented with pressure-tip micromanometers placed in the apex and outflow tract of the left ventricular (LV) cavity and with sonomicrometer crystals placed in the apex and base of the LV free wall to measure IVPGs and myocardial segment length changes during basal, afterloaded (aortic cross-clamping) and ischaemic conditions (left anterior descending coronary artery ligation). During early diastole (rapid filling), we recorded an IVPG (4.6 ± 0.7 mmHg) from the cardiac base towards the apex followed by an apex-to-outflow pressure gradient (3.6 ± 0.2 mmHg). During systole, we recorded an IVPG (0.6 ± 0.1 mmHg) from apex to outflow during early rapid ejection, which inverted during late slow ejection. Interestingly, the maximal rate of LV pressure fall occurred earlier and relaxation rate was faster in the base than in the apex. While shortening of basal segments was complete at the end of ejection, apical segments always showed a significant amount of postsystolic shortening. The IVPGs were entirely lost during ischaemia and attenuated by afterload elevations. During ischaemia, systolic shortening of the apical segment decreased, while postsystolic shortening increased. The present study confirms the existence of diastolic and systolic IVPGs in the LV and demonstrates, for the first time, that this normal gradient pattern is related to physiological asynchrony between basal and apical myocardial segments. Moreover, we show that the IVPG, a marker of normal left ventricular function, can be attenuated, lost entirely or even reversed after regional acute ischaemia and afterload elevations.