Torrential mitral regurgitation following right ventricular apical pacing in rheumatic mitral valve disease: a case report

Background Mitral regurgitation may develop or worsen following right ventricular apical pacing due to dyssynchronous left ventricular contraction. Pre-existing secondary mitral annular dilation is a well-recognized and important contributing factor. This description of pacing-induced torrential mitral regurgitation in the setting of rheumatic mitral valve disease is a rare case in which a primary mitral valve lesion was the antecedent mechanism. Case summary A 60-year-old man was admitted with dizziness and pre-syncope. Twelve-lead electrocardiogram showed complete heart block. A dual-chamber pacemaker was implanted and programmed in DDD mode. Transthoracic echocardiography performed a day later demonstrated a left ventricular ejection fraction (LVEF) of 63% and moderate mitral regurgitation. The patient presented 4 months later with breathlessness and orthopnoea. Pacemaker interrogation demonstrated a 98% right ventricular pacing burden. Echocardiography revealed torrential mitral regurgitation secondary to left ventricular dyssynchrony and complete loss of leaflet coaptation with preserved systolic function. Post-capillary pulmonary hypertension was diagnosed following right heart catheterization. The patient underwent metallic mitral valve replacement, tricuspid annuloplasty, and left internal mammary artery grafting to the left anterior descending artery for a severe proximal stenosis. On inspection, the native mitral valve was notably rheumatic in appearance, and this was confirmed histologically. Discussion It is important to closely monitor the progression of mitral regurgitation in those with primary mitral valve disease undergoing right ventricular pacing. Early follow-up may prevent the adverse haemodynamic consequences of worsening mitral regurgitation, with a greater chance of recovery of left ventricular function following surgery

Central and peripheral quadriceps fatigue in congestive heart failure

AbstractAimsThe clinical syndrome of heart failure includes exercise limitation that is not directly linked to measures of cardiac function. Quadriceps fatigability may be an important component of this and this may arise from peripheral or central factors.Methods and resultsWe studied 10 men with CHF and 10 healthy age-matched controls. Compared with a rest condition, 10min after incremental maximal cycle exercise, twitch quadriceps force in response to supramaximal magnetic femoral nerve stimulation fell in both groups (CHF 14.1%±18.1%, p=0.037; Control: 20.8±11.0%, p<0.001; no significant difference between groups). There was no significant change in quadriceps maximum voluntary contraction voluntary force. The difference in the motor evoked potential (MEP) response to transcranial magnetic stimulation of the motor cortex between rest and exercise conditions at 10min, normalised to the peripheral action potential, also fell significantly in both groups (CHF: 27.3±38.7%, p=0.037; Control: 41.1±47.7%, p=0.024). However, the fall in MEP was sustained for a longer period in controls than in patients (p=0.048).ConclusionsThe quadriceps is more susceptible to fatigue, with a similar fall in TwQ occurring in CHF patients at lower levels of exercise. This is associated with no change in voluntary activation but a lesser degree of depression of quadriceps motor evoked potential

Correlation between echocardiographic and hemodynamic variables in cardiothoracic intensive care unit

Objectives the echocardiographic indices have not been validated in critically ill population. We investigated the correlation between some echocardiographic and hemodynamics parameters. Design Prospective Spontaneous non-interventional observational study. Setting Adult cardiothoracic intensive care unit, single center (Royal Brompton Hospital, London UK). Participants Consecutive adult patients admitted to cardiothoracic intensive care unit for severe respiratory failure, primary cardio-circulatory failure and post-aortic surgery. Interventions Clinical, hemodynamic parameters (stroke volume – SV, cardiac output – CO, mean arterial pressure – MAP, and cardiac power index – CPI) and echocardiographic indices of ventricular function (left ventricular total isovolumic time – t-IVT, mitral annular plane systolic excursion – MAPSE, and left ventricular fraction – LVEF) were evaluated offline. Measurements and main results 117 patients were studied (age 57.2 ± 19; 60.6% male). t-IVT showed an inverse correlation with SV, CO, MAP and CPI (respectively r: -67%; -38%; -45%; -51%). MAPSE exhibited a positive correlation with SV, CO, MAP and CPI (respectively r: 43%; 44%; 34%; 31%). LVEF did not show any correlation. In the multivariate analysis the association of t-IVT and hemodynamics was confirmed for SV, CO, MAP and CPI with the highest partial correlation between t-IVT and MAP (R = -58%). Conclusions MAPSE and t-IVT are two reproducible and reliable echocardiographic indices of systolic function and ventricular efficacy associated with hemodynamic variables in cardiothoracic critically ill patients, while LVEF did not show any correlation

Association between mid-wall late gadolinium enhancement and sudden cardiac death in patients with dilated cardiomyopathy and mild and moderate left ventricular systolic dysfunction

Background—Current guidelines only recommend the use of an implantable cardioverter defibrillator (ICD) in patients with dilated cardiomyopathy (DCM) for the primary prevention of sudden cardiac death (SCD) in those with a left ventricular ejection fraction (LVEF)35%. Patients with a LVEF>35% also have low competing risks of death from non-sudden causes. Therefore, those at high-risk of SCD may gain longevity from successful ICD therapy. We investigated whether late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) identified patients with DCM without severe LV systolic dysfunction at high-risk of SCD. Methods—We prospectively investigated the association between mid-wall late gadolinium enhancement (LGE) and the pre-specified primary composite outcome of SCD or aborted SCD amongst consecutive referrals with DCM and a LVEF≥40% to our center between January 2000 and December 2011, who did not have a pre-existing indication for ICD implantation. Results—Of 399 patients (145 women, median age 50 years, median LVEF 50%, 25.3% with LGE) followed for a median of 4.6 years, 18 of 101 (17.8%) patients with LGE reached the pre-specified end-point, compared to 7 of 298 (2.3%) without (HR 9.2; 95% CI 3.9-21.8; p5% compared to those without LGE were 10.6 (95%CI 3.9-29.4), 4.9 (95% CI 1.3-18.9) and 11.8 (95% CI 4.3-32.3) respectively. Conclusions—Mid-wall LGE identifies a group of patients with DCM and LVEF≥40% at increased risk of SCD and low-risk of non-sudden death who may benefit from ICD implantation

The family as a determinant of stunting in children living in conditions of extreme poverty: a case-control study

BACKGROUND: Malnutrition in children can be a consequence of unfavourable socioeconomic conditions. However, some families maintain adequate nutritional status in their children despite living in poverty. The aim of this study was to ascertain whether family-related factors are determinants of stunting in young Mexican children living in extreme poverty, and whether these factors differ between rural or urban contexts. METHODS: A case-control study was conducted in one rural and one urban extreme poverty level areas in Mexico. Cases comprised stunted children aged between 6 and 23 months. Controls were well-nourished children. Independent variables were defined in five dimensions: family characteristics; family income; household allocation of resources and family organisation; social networks; and child health care. Information was collected from 108 cases and 139 controls in the rural area and from 198 cases and 211 controls in the urban area. Statistical analysis was carried out separately for each area; unconditional multiple logistic regression analyses were performed to obtain the best explanatory model for stunting. RESULTS: In the rural area, a greater risk of stunting was associated with father's occupation as farmer and the presence of family networks for child care. The greatest protective effect was found in children cared for exclusively by their mothers. In the urban area, risk factors for stunting were father with unstable job, presence of small social networks, low rate of attendance to the Well Child Program activities, breast-feeding longer than six months, and two variables within the family characteristics dimension (longer duration of parents' union and migration from rural to urban area). CONCLUSIONS: This study suggests the influence of the family on the nutritional status of children under two years of age living in extreme poverty areas. Factors associated with stunting were different in rural and urban communities. Therefore, developing and implementing health programs to tackle malnutrition should take into account such differences that are consequence of the social, economic, and cultural contexts in which the family lives

Changes in clinical and imaging variables during withdrawal of heart failure therapy in recovered dilated cardiomyopathy.

AIMS: This study aimed to profile the changes in non-invasive clinical, biochemical, and imaging markers during withdrawal of therapy in patients with recovered dilated cardiomyopathy, providing insights into the pathophysiology of relapse. METHODS AND RESULTS: Clinical, biochemical, and imaging data from patients during phased withdrawal of therapy in the randomized or single-arm cross-over phases of TRED-HF were profiled. Clinical variables were measured at each study visit and imaging variables were measured at baseline, 16 weeks, and 6 months. Amongst the 49 patients [35% women, mean age 53.6 years (standard deviation 11.6)] who withdrew therapy, 20 relapsed. Increases in mean heart rate [7.6 beats per minute (95% confidence interval, CI, 4.5, 10.7)], systolic blood pressure [6.6 mmHg (95% CI 2.7, 10.5)], and diastolic blood pressure [5.8 mmHg (95% CI 3.1, 8.5)] were observed within 4-8 weeks of starting to withdraw therapy. A rise in mean left ventricular (LV) mass [5.1 g/m2 (95% CI 2.8, 7.3)] and LV end-diastolic volume [3.9 mL/m2 (95% CI 1.1, 6.7)] and a reduction in mean LV ejection fraction [-4.2 (95% CI -6.6, -1.8)] were seen by 16 weeks, the earliest imaging follow-up. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) fell immediately after withdrawing beta-blockers and only tended to increase 6 months after beginning therapy withdrawal [mean change in log NT-proBNP at 6 months: 0.2 (95% CI -0.1, 0.4)]. CONCLUSIONS: Changes in plasma NT-proBNP are a late feature of relapse, often months after a reduction in LV function. A rise in heart rate and blood pressure is observed soon after withdrawing therapy in recovered dilated cardiomyopathy, typically accompanied or closely followed by early changes in LV structure and function

Relationship between heart rate and outcomes in patients in sinus rhythm or atrial fibrillation with heart failure and reduced ejection fraction

Aims: To investigate the relationship between heart rate and outcomes in heart failure and reduced ejection fraction (HFrEF) patients in sinus rhythm (SR) and atrial fibrillation (AF) adjusting for natriuretic peptide concentration, a powerful prognosticator. Methods and results: Of 13 562 patients from two large HFrEF trials, 10 113 (74.6%) were in SR and 3449 (25.4%) in AF. The primary endpoint was the composite of cardiovascular death or heart failure hospitalization. Heart rate was analysed as a categorical (tertiles, T1–3) and continuous variable (per 10 bpm), separately in patients in SR and AF. Outcomes were adjusted for prognostic variables, including N‐terminal prohormone of B‐type natriuretic peptide (NT‐proBNP), and also examined using change from baseline heart rate to 1 year (≤ −10 bpm, ≥ +10 bpm, &lt; ±10 bpm). SR patients with a higher heart rate had worse symptoms and quality of life, more often had diabetes and higher NT‐proBNP concentrations. They had higher risk of the primary endpoint [T3 vs. T1 adjusted hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.35–1.66; P &lt; 0.001; per 10 bpm: 1.12, 95% CI 1.09–1.16; P &lt; 0.001]. In SR, heart rate was associated with a relatively higher risk of pump failure than sudden death (adjusted HR per 10 bpm 1.17, 95% CI 1.09–1.26; P &lt; 0.001 vs. 1.07, 95% CI 1.02–1.13; P = 0.011). Heart rate was not predictive of any outcome in AF. Conclusions: In HFrEF, an elevated heart rate was an independent predictor of adverse cardiovascular outcomes in patients in SR, even after adjustment for NT‐proBNP. There was no relationship between heart rate and outcomes in AF