Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ventricular dysfunction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed2000

Influence of left ventricular dysfunction on the role of atrial contraction: an echocardiographic-hemodynamic study in dogs.

OBJECTIVES: The purpose of this study was to understand the significance of an effective atrial systole and the interactions between atrial and ventricular function. BACKGROUND: The significance of atrial function is controversial, particularly in the setting of left ventricular (LV) dysfunction. METHODS: Serial, rapid pacing in five dogs that had undergone radiofrequency ablation and implantation of right atrial and ventricular pacemakers produced reversible atrial and ventricular dysfunction (alone and in combination). Atrial function (echocardiograph-determined transmitral diastolic flow, left atrial appendage emptying, and pulmonary venous flow), cardiac output, and right heart pressures were measured at matched paced heart rates of 80 beats/min. RESULTS: Isolated rapid atrial pacing (LV ejection fraction approximately 60%) decreased atrial booster pump in the body and appendage of the left atrium, but increased the conduit function of the left atrium. Isolated LV dysfunction (LV ejection fraction approximately 34%) increased atrial booster pump function. The decreased atrial booster pump function in animals with combined atrial and ventricular dysfunction was incompletely compensated by the redistribution of the reservoir and conduit functions of the left atrium. As a result, cardiac output decreased and right heart pressures increased only after superimposed pacing. CONCLUSIONS: In the presence of a normal left ventricle (LV), atrial failure has little effect on cardiac output and right heart pressures because of compensatory conduit function, but when early LV dysfunction coexists, changes in reservoir and conduit functions are insufficient to compensate for an impairment of atrial contraction.

Animals↗
PubMed1981

Complex ventricular arrhythmias after myocardial infarction during convalescence and follow-up: a harbinger of multi-vessel coronary disease, left ventricular dysfunction and sudden death.

Sixty-one medically treated patients had coronary and left ventricular angiography and 24-hour electrocardiographic monitoring 10-24 days after myocardial infarction, and then had serial 24-hour electrocardiographic monitoring during the 13 +/- 11 months after myocardial infarction. Complex ventricular arrhythmias (2 or more sequential ventricular premature depolarizations (VPDs), multiform VPDs, bigeminy) during follow-up were associated with a high mortality rate and occurred most commonly in the setting of three-vessel coronary disease, proximal left anterior descending coronary disease and low left ventricular ejection fraction. By contrast, patients without complex VPDs in either the late hospital or posthospital phase of myocardial infarction had no mortality during the year following myocardial infarction; furthermore, these patients had a higher incidence of single-vessel coronary disease and less left ventricular dysfunction. These results emphasize the adverse prognostic significance of complex ventricular arrhythmias in the year after myocardial infarction and their association with extensive coronary artery disease and left ventricular damage.

Arrhythmias, Cardiac↗
PubMed1995

Left ventricular dysfunction induced by occlusion of coronary arteries in conscious dogs.

The aim of the present study was to investigate stable left ventricular dysfunction resulting from severe myocardial ischemia in conscious dogs, in order to evaluate the action of cardiotonic agents under pathological conditions mimicking moderate cardiac failure. Mongrel dogs with a catheter implanted in the left ventricle were trained on a treadmill and subjected to a standardized exercise before and after a Harris-type ligation of the anterior descending branch of the left coronary artery in two stages. Two weeks later the lower third of the left circumflex coronary branch was also occluded, and the exercise test repeated for at least two additional weeks to evaluate the changes in the left ventricular function indicated by left ventricular systolic pressure, end-diastolic pressure, heart rate, positive and negative dP/dtmax and dP/dt/P. Noninvasive radionuclide investigations of the left ventricular function and myocardial perfusion were done before and after the development of cardiac failure. Following occlusion of the anterior descending and circumflex coronary arteries, the baseline end-diastolic pressure increased from 7.6 +/- 2.3 mmHg to 23.3 +/- 3.0 mmHg (p < 0.05) and increased even further during exercise (to 49.2 +/- 3.5 mmHg, p < 0.05). After the development of cardiac failure, no substantial change occurred in the end-diastolic pressure, either during rest or repeated exercise tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Analysis of left ventricular function early after coronary artery bypass grating in patients with left ventricular dysfunction].

We analyzed left ventricular (LV) function early after coronary artery bypass grafting (CABG) in patients with LV dysfunction, whose LV ejection fraction (LVEF) was less than 0.4. 11 patients were divided into two groups: Group-A patients (G-A: n = 6) improved LVEF (post-op LVEF > 0.4) and Group-B patients (G-B: n + 5) did not improve LVEF (post-op LVEF < 0.4) one month after CABG. Preoperative status of coronary artery disease, cardiac function, operative procedure, and postoperative cardiac function were compared between two groups. All patient had old myocardial infarction. There were no differences in preoperative LVEF (0.30 +/- 0.06 in G-A and 0.31 +/- 0.06 in G-B), CI, and LVEDP between two groups. LVEDVI (85 +/- 19 in G-A and 159 +/- 50 ml/m2 in G-B) and LVESVI (60 +/- 14 in G-A and 113 +/- 49 ml/m2 in G-B) values were higher in G-B, respectively. Number of grafts was not different between two groups (2.3 in G-A and 2.4 in G-B). Postoperative LVEF value (0.53 +/- 0.07 in G-A and 0.34 +/- 0.04 in G-B) was lower in G-B. Thus, it might be difficult to obtain the recovery of LV function in patients with LV dilatation, early after CABG.

Adult↗
PubMed1993

Repetitively negative changing T waves at 24-h electrocardiographic monitors in patients with the chronic fatigue syndrome. Left ventricular dysfunction in a cohort.

This study surveys the occurrence of repetitively negative to flat T waves, alternating with normal upright T waves in 24-h electrocardiographic recordings from a subspecialty infectious diseases outpatient practice during the years 1982 to 1990. Patients with normal resting electrocardiogram in the assayed leads, but with repetitively inverted to isoelectric abnormal T waves at Holter monitors, were considered to have abnormal readings. A total of 300 patients had undergone a 24-h Holter monitor. This group included 24 individuals with chronic fatigue syndrome (CFS). This population was restricted to individuals 50 years old or younger, and the patients with CFS are compared with the patients without CFS. One of the more striking differences between the two groups was the difference in abnormal Holter readings. The patients with CFS all had abnormal Holter readings, while 22.4 percent patients without CFS had abnormal readings (p < 0.01). We further report the occurrence of mild left ventricular dysfunction in 8 of 60 patients in continuing studies of this population with CFS, younger than 50 years old, and with no risk factors for coronary artery disease. All 60 patients with CFS showed repetitively flat to inverted T waves alternating with normal T waves. Stress multiple gated acquisitions (MUGAs) (labeled erythrocytes with stannous pyrophosphate) were abnormal in eight patients with CFS. Although resting ejection fractions (EFs) were normal (mean, 60 percent), with increasing work loads (Kilopon meters [Kpms]), gross left ventricular dysfunction occurred. The fatigue of patients with CFS may be related to subtle cardiac dysfunction occurring at work loads common to ordinary living.

Adult↗
PubMed1995

[Exercise capacity evaluation in patients with mild to moderate left ventricular dysfunction. Influence of captopril].

PURPOSE: To analyse the captopril influence on physical activity on the six or nine minute walk test in patients with left ventricular dysfunction and mild or moderate failure. METHODS: Twenty one patients with functional class II or III heart failure and left ventricular diastolic diameter greater than 55 mm and with ejection fraction less than 45% were studied. Twelve were male, and the patients age range from 34 to 63 years old (mean 48 years). The protocol has 18 weeks of duration, the first two weeks constitute a washout period, and 16 of effective use of captopril 25 mg tid. The patients were submitted to clinical and laboratory evaluations, to echocardiogram study and six and nine minute walk test (distance of walk), before, through out, and after the protocol. RESULTS: The distance of walk on six minute test were 451 m at the beginning, and 476 m in 4 weeks and 504 m at 16 weeks of treatment (p < 0.0001). At nine minute test it was respectively 599, 652 and 692 m (p < 0.001). The echocardiographic evaluation showed significative reduction of the left ventricular diastolic diameter and an increase of the left ventricular ejection fraction. The clinical evaluation after the treatment showed that 45% comes to functional class I, and only 10% stayed in class III. CONCLUSION: Captopril 25 mg tid improves clinical performance significantly, with improvement of walk distance at six or nine minute of test, and with reduction of left ventricular end diastolic diameter and systolic function improvement. The results permits to conclude that captopril improves significantly the physical activity of patients with heart failure, this improves were observed with one months of therapy but is more evident with four months of effective treatment.

Adult↗
PubMed2003

[Exercise echocardiography to differentiate dilated cardiomyopathy from ischemic left ventricular dysfunction].

OBJECTIVES: Previous studies have shown the usefulness of dobutamine echocardiography to differentiate dilated cardiomyopathy (DC) from ischemic left ventricular dysfunction (ILVD), but no studies have been made using exercise echocardiography (EE). We hypothesized that most patients with DC have some contractile reserve and experience an increase in left ventricular ejection fraction (LVEF) during exercise, as opposed to patients with ILVD. Differences in response to EE may be useful to clinically differentiate between these two entities. PATIENTS AND METHOD: Between 1 March 1995 and 1 March 2001, we performed 4,133 EE studies on 3,830 patients. Of 289 patients (8%) with moderate or severe LV dysfunction (biplane LVEF < 41% and left ventricular end-diastolic diameter > 5.2 cm), 207 were excluded: 111 for a history of myocardial infarction; 28 for scarring on echocardiography (regional akinesia/dyskinesia with thinning and/or increased brightness); 13 for previous revascularization procedures; 9 for aortic valve disease; 11 for a known cause of cardiomyopathy; and 35 for not undergoing angiography. The study group was therefore composed of 82 patients who were encouraged to perform maximal treadmill EE. EE criteria for ILVD were either impaired regional wall motion (RWM) or a decrease/no change in LVEF from baseline to peak exercise, while criteria for DC were RWM improvement/no change and LVEF increase. The ILVD group was formed by 39 patients with stenosis >/= 70% diameter stenosis of a major epicardial coronary artery or major branch vessel. The remaining 43 patients constituted the DC group. RESULTS: The number of coronary risk factors (ILVD 2.0 1.1; DC 1.9 1.1), baseline LVEF (ILVD 30 7; DC 30 8), and exercise-induced angina (ILVD 23%; DC 14%) did not differ between groups (p = NS). ILVD patients achieved less Mets (6.6 3.1 vs 8.3 2.8; p < 0.05), had a lower heart rate x systolic blood pressure product (22 5 vs 27 7; p < 0.001), and developed regional and/or global LV dysfunction more frequently (79 vs 28%; p < 0.001). Sensitivity, specificity, positive and negative predictive values and global accuracy for ILVD detection were 79% (95% CI: 70-88), 72% (95% CI: 63-81), 72% (95% CI: 63-81), 79% (95% CI: 67-85), and 76% (95% CI: 69-83), respectively. CONCLUSION: Global and/or regional LV function impairment with exercise is accurate in identifying patients with ILVD. This method could reduce the need for invasive procedures.

Aged↗
PubMed1994

Coronary artery by-pass without cardiopulmonary by-pass for patients with severe left ventricular dysfunction.

OBJECTIVES: To evaluate results of coronary artery bypass grafting (CABG) without cardiopulmonary by-pass (CPB) for patients with severe left ventricular dysfunction. MATERIALS AND METHODS: Fifty-three patients with severe LV dysfunction (EF < 35%) underwent CABG without cardiopulmonary by-pass (CPB) between December 1991 and December 1993. They comprise 22% of 242 patients operated on without CPB by one of the authors (RM) in this period. There were 45 (85%) males and eight (15%) females. Twelve (23%) patients were over 70 years. Nine (17%) were re-do CABG. Ten (19%) were referred for operation within the first 24 hours of evolving MI, and 13 (25%) up to two weeks after acute MI. Nine (17%) had preoperative EF < 20%, and six patients (11%) were in cardiogenic shock. Mean number of grafts/pt was 1.8 and IMA was used in 41 (77%). Only 14 patients (26%) received a graft to a circumflex marginal artery. Ischemic time was 8 +/- 4 min/graft (mean +/- SD) when anastomosed to the LAD or RCA, and 14 +/- 7 min/graft when anastomosed to a marginal branch. RESULTS: One patient (1.9%) died perioperatively, and two (3.7%) suffered a non-fatal MI. At two-year follow-up there were three late deaths, one of them from cancer. Three patients had return of angina, two of them were reoperated upon. CONCLUSIONS: These results suggest that CABG without CPB may be advantageous for patients with severe LV dysfunction.

Adult↗
PubMed1999

Assessment of the stability of N-terminal pro-brain natriuretic peptide in vitro: implications for assessment of left ventricular dysfunction.

Plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) are raised in patients with left ventricular dysfunction. Measurement of this peptide has a potential diagnostic role in the identification and assessment of patients with heart failure. The stability of this peptide over time periods and conditions pertaining to routine clinical practice has not been reported previously. Blood samples were obtained from 15 subjects. One aliquot was processed immediately, and the remaining portions of the blood samples were stored for 24 h or 48 h at room temperature or on ice prior to processing. Plasma concentrations of NT-proBNP were measured with a novel immunoluminometric assay developed within our laboratory. Mean plasma concentrations of NT-proBNP were not significantly different whether blood samples were centrifuged immediately and stored at -70 degrees C or kept at room temperature or on ice for 24 h or 48 h. The mean percentage differences from baseline (reference standard) were +5.2% (95% confidence interval +18.2 to -7.8%) and +0.8% (+15.2 to -13.7%) after storage for 24 h at room temperature or on ice respectively, and +8.9% (+24.2 to -6. 5%) and +3.2% (+15.1 to -0.9%) for storage for 48 h at room temperature or on ice respectively. Pearson correlation coefficients for baseline NT-proBNP concentrations compared with levels at 48 h at room temperature or on ice were r=0.89 and r=0.83 respectively (both P<0.0001). Thus NT-proBNP extracted from plasma samples treated with EDTA and aprotinin is stable under conditions relevant to clinical practice.

Adult↗
PubMed2000

Determinants of the degree of functional mitral regurgitation in patients with systolic left ventricular dysfunction: A quantitative clinical study.

BACKGROUND: Functional mitral regurgitation (FMR) occurs with a structurally normal valve as a complication of systolic left ventricular dysfunction (LVD). Determinants of degree of FMR are poorly defined; thus, mechanistic therapeutic approaches to FMR are hindered. METHODS AND RESULTS: In a prospective study of 21 control subjects and 128 patients with LVD (defined as ejection fraction <50%, mean 31+/-9%) in sinus rhythm, we quantified simultaneously by echocardiography the effective regurgitant orifice (ERO) of FMR by using 2 methods: mitral deformation (valve and annulus) and left ventricular (LV) global (volumes, stress, function, and sphericity) and local (papillary muscle displacements and regional wall motion index) remodeling. A wide range of ERO (15+/-14 mm(2), 0 to 87 mm(2)) was observed, unrelated to ejection fraction (P:=0.32). The major determinant of ERO was mitral deformation, ie, systolic valvular tenting and annular contraction in univariate (r=0.74 and r=-0.61, respectively; both P:<0.0001) and multivariate (both P:<0. 0001) analyses, independent of global LV remodeling. Systolic valvular tenting was strongly determined by local LV alterations, particularly apical (r=0.75) and posterior (r=0.70) displacement of papillary muscle, with confirmation in multivariate analysis (both P:<0.0001), independent of LV volumes, function, and sphericity. CONCLUSIONS: The presence and degree of FMR complicating LVD are unrelated to the severity of LVD. Local LV remodeling (apical and posterior displacement of papillary muscles) leads to excess valvular tenting independent of global LV remodeling. In turn, excess tenting and loss of systolic annular contraction are associated with larger EROs. These determinants of FMR warrant consideration for specific approaches to the treatment of FMR complicating LVD.

Aged↗
PubMed2003

Importance of ischemic and viable myocardium for patients with chronic ischemic mitral regurgitation and left ventricular dysfunction.

The objective of this investigation is to determine the importance of ischemic viable myocardium for clinical outcomes in patients with severe chronic ischemic mitral regurgitation and severe left ventricular dysfunction undergoing surgical correction of mitral regurgitation. The study included 54 patients with left ventricular ejection fraction of 27 +/- 9%. Positron emission tomography was performed preoperatively for the identification of ischemic viable myocardium. The patients with a large amount of ischemic viable myocardium (> or =5 segments) had significantly lower 6-month mortality rates than those with less viable myocardium (0 to 4 segments) after the surgery.

Cause of Death↗
PubMed1986

Left ventricular dysfunction versus paravalvular leak in patients with mitral disc prostheses.

UNLABELLED: Left ventricular dysfunction and prosthesis malfunction are the main causes of hemodynamic deterioration following prosthetic mitral valve replacement. The aim of this study is to reassess the usefulness of a combined echo-phonocardiographic technique to differentiate these different situations in order to select medical or surgical treatment in patients with a mitral disc prosthesis. Two patient groups were studied. The first group consists of five patients with paravalvular leak (PL), surgically or pathologically verified. Second group: nine patients with left ventricular failure (LVF) and normal functioning prosthesis. The diastolic diameter of the left ventricle (LV) was significantly increased in the LVF group compared with the PL group. A protodiastolic hump was present in four cases of PL. The variability of the interval between A2 and the mitral valve opening (delta A2-MVO) was less than 30 msec in the LVF group and greater than 30 msec in the PL group. The interval between A2 and maximal LV posterior wall (A2-PW) exceeded 60 msec in the PL group and was shorter than 60 msec in the LVF group. IN CONCLUSION: the echo-phonocardiographic technique, especially when by using two newly proposed parameters, seems to be very useful to discriminate between PL and LVF.

Adult↗
PubMed1991

[CABG in 2 patients with severe left ventricular dysfunction].

Coronary artery bypass grafting was performed in two patients with left ventricular dysfunction (EF 16%). In both cases they had chest pain at rest and ischemic myocardium were detected by the SPECT. We considered them candidate for the operation regardless of LV dysfunction. They were eventful in the postoperative course. One case was discharged and is free from chest pain now, but another unfortunately died for multiple organ failure.

Coronary Artery Bypass↗
PubMed1990

Studies of left ventricular dysfunction (SOLVD)--rationale, design and methods: two trials that evaluate the effect of enalapril in patients with reduced ejection fraction.

The Studies of Left Ventricular Dysfunction (SOLVD) is an extensive program of research that has 3 components. (1) Two large double-blind randomized trials evaluate the effects of enalapril on mortality, morbidity and quality of life of patients with left ventricular (LV) dysfunction with overt congestive heart failure (CHF) (Treatment Trial in 2,500 patients) and without overt CHF (Prevention Trial in 4,600 patients). (2) Seven detailed sub-studies evaluate the effect of enalapril on a number of intermediate outcomes such as right and LV function and hemodynamics, LV mass and wall stress, hormones, arrhythmias, exercise capacity and quality of life in subsets of patients in the 2 large trials. (3) Finally, a registry of 6,336 patients with congestive heart failure or LV dysfunction is designed to describe the clinical course of an unselected group of patients. The rationale and design of a tiered approach to clinical trials that are large enough to provide reliable information on mortality and morbidity, yet provide relevant information on other endpoints, are described.

Adult↗
PubMed2002

Recovery kinetics of oxygen uptake after cardiopulmonary exercise test and prognosis in patients with left ventricular dysfunction.

INTRODUCTION: The prognostic value of peak oxygen uptake (peak VO2) in patients with left ventricular systolic dysfunction is currently recognized and accepted. Some studies have shown that other cardiopulmonary exercise test (CPET) parameters have additional value. OBJECTIVES: To evaluate whether our population of patients with left ventricular dysfunction had similar results to those found by other investigators who showed that a slow normalization of oxygen uptake (VO2) during the recovery period of a CPET has prognostic value, and whether the recovery phase parameters have additional prognostic value to peak VO2 in these patients. METHODS: We studied 292 consecutive adult patients (81.5% male; mean age 52.4 +/- 10.6 years) with an ejection fraction below 40% (mean 23.6 +/- 8.8%) given their first symptom-limited CPET between 03/1993 and 08/2000. The etiology was ischemic heart disease in 154, idiopathic cardiomyopathy in 130 and other in 8 patients. NYHA class was I in 7%, II in 50.6% and III in 42.4% of the patients. Two years was defined as the maximum follow-up time; it was 551.5 +/- 242.2 days on average, and 62 events (death or cardiac transplantation) occurred. The following parameters were analyzed: peak VO2 (l/min and ml/kg/min), percent predicted peak VO2 (pred VO2) (l/min and ml/kg/min), VO2 every 15 seconds (sec) of the first 3 minutes of recovery (the difference between peak VO2/kg and VO2/kg every 15 sec in the recovery period (dif VO2), expressed in ml/kg/min, and also the time (sec) to reach 50% of peak VO2 (T1/2). It was considered that a combined end-point was reached if patients died or underwent cardiac transplantation. RESULTS: ROC curves of these parameters showed the following as cut-off values (area under the curve > 0.7) for the occurrence of events: peak VO2 < 60% of pred VO2, dif VO2 at 60 sec (< 3 ml/kg/min), 90 sec (< 5), 120 sec (< 8), 150 sec (< 8.6) and 180 sec (< 10.5) of the recovery and T1/2 > 115 sec. Survival analysis was performed considering pred VO2 < 60%, dif VO2 at 150 sec (the largest area under the curve) and T1/2 > 115 sec. In the survival analysis, when the decrease in VO2 at 150 sec was less than 8.6 ml/kg/min the number of patients with events increased from 9.2% to 43.5% (p < 0.001; log-rank), and when T1/2 was less than 115 sec the number of events increased from 12.3 to 34.2% (p < 0.001; log-rank). When the criteria of T1/2 and dif VO2 at 150 sec were considered together with pred VO2 < 60%, mortality increased from 31 to 54% and from 33 to 51%, respectively (p < 0.001, for both parameters; chi-square). CONCLUSIONS: A slow VO2 kinetics in the recovery period of the CPET by itself identified groups of patients with poor prognosis. The association of these parameters with peak VO2 enhanced the identification of groups at greater risk for events. A global evaluation of the CPET should be performed, considering other parameters besides peak VO2, particularly those related to VO2 kinetics in recovery (T1/2 and dif VO2 at 150 sec) as identified in this study.

Adolescent↗
PubMed1997

Minimal operative mortality in patients undergoing coronary artery bypass with significant left ventricular dysfunction by maximization of metabolic and mechanical support.

Between January 1, 1992, and January 23, 1996, 111 consecutive patients with severe left ventricular dysfunction underwent isolated coronary artery bypass grafting. The ejection fraction in these patients ranged from 10% to 34% (mean 27.9% +/- 5.4%); in 18 patients the value was less than 20%. The high operative mortality rate (7.6% in Society of Thoracic Surgeons database) in this group of patients at high risk was targeted for reduction by provision of, in addition to the usual inotropic support, progressively more intensive metabolic and mechanical support. The metabolic support consisted of triiodothyronine; glucose, insulin, and potassium; aspartate/glutamate in the cardioplegic solution; and warm-cold-warm/antegrade-retrograde-antegrade cardioplegia. Mechanical support included liberal use of the intraaortic balloon pump, use of a new occlusive retrograde cardioplegia catheter, ultrafiltration to remove myocardial depressant factors, and, finally, delayed sternal closure. The operative mortality rate was 1.8% (2/111). Complications included reoperation because of bleeding (3.6%, 4/111), mediastinitis (1.8%, 2/111), and stroke (0.9%, 1/111) and there were no occurrences of new postoperative acute renal failure (0.0%, 0/111). The intensive care unit stay was 2.2 +/- 0.9 days with a length of stay in the hospital of 13.7 +/- 22.1 days. These techniques done before operation, intraoperatively, and postoperatively optimize the milieu of the depressed left ventricle by maximizing perioperative high-energy phosphate bonds; increasing the effectiveness of inotropic agents; unloading the left ventricle by chemical, metabolic, and mechanical support; and removing known myocardial depressant factors, which reduced the operative mortality rate to 1.8% compared with 7.6% as reported in the Society of Thoracic Surgeons' database.

Adult↗
PubMed2006

Myocardial ischemia and right ventricular dysfunction in adult patients with sickle cell disease.

BACKGROUND AND OBJECTIVES: Patients with sickle cell disease (SCD) have multi-organ manifestations of microvascular disease, though cardiac manifestations have been poorly characterized in vivo. This study sought to characterize myocardial characteristics in adult patients with SCD. DESIGN AND METHODS: Twenty-two consecutive outpatients and 11 age-matched controls underwent magnetic resonance imaging to assess myocardial perfusion reserve as well as left and right ventricular size and function and myocardial iron. Computed tomography of the coronary arteries was performed to assess epicardial coronary stenosis. RESULTS: Three of 22 outpatients with clinically stable SCD and no controls had abnormal myocardial perfusion reserve limited to the subendocardium, consistent with microvascular disease. Coronary arteries were free of disease as detectable by computed tomography angiography. Myocardial T2* was normal in all subjects (29 +/- 5 ms, median 29 ms), consistent with absence of cardiac iron deposition despite a high prevalence of hepatic iron overload (liver T2* 14 +/- 9 ms, median 12.0 ms). SCD patients had right ventricular enlargement and dysfunction (right ventricular ejection fraction 45 +/- 15 in SCD patients vs. 58 +/- 5% in controls, p=0.001) even in the absence of overt pulmonary hypertension. INTERPRETATION AND CONCLUSIONS: A subset of adult SCD patients may have myocardial ischemia in the absence of infarcted myocardium, myocardial iron overload, or coronary artery disease. Right ventricular dysfunction is present in stable SCD patients, despite normal resting pulmonary artery pressures. These findings could represent under-recognized mechanisms for chest pain and mortality in this population, and warrant further investigation in SCD crises.

Adult↗
PubMed2006

Critical level of cerebral oxygenation during exercise in patients with left ventricular dysfunction.

BACKGROUND: In a recent study the indexes of cerebral oxygenation decreased during maximal exercise in nearly half of all patients with left ventricular dysfunction. Whether these levels decrease severely enough to influence mental status or level of consciousness was evaluated in the present study. METHODS AND RESULTS: Forty-two patients with idiopathic dilated cardiomyopathy (IDC) and 29 healthy subjects underwent a symptom-limited maximal exercise test. The cerebral oxyhemoglobin (O(2)Hb) and tissue oxygenation index (TOI) were continuously monitored using near-infrared spectroscopy. The changes in O(2)Hb and TOI were also measured in 7 subjects: 2 who experienced episodes of reduced consciousness caused by sudden decreases in blood pressure during exercise recovery and 5 who exhibited sustained ventricular tachycardia during an electrophysiological study. The change in cerebral O(2)Hb during exercise in patients with IDC averaged 0.38+/-3.39 micromol/L, significantly lower than in the normal subjects (4.30+/-4.47 micromol/L, p<0.0001). The cerebral O(2)Hb decreased during exercise in 18 of 42 patients with IDC. The change in cerebral TOI in the IDC patients during exercise was significantly less than that in the normal subjects (-2.0+/-4.7 vs 2.1+/-5.8%, p=0.002). The mean decreases in cerebral O(2)Hb and TOI were -5.34 micromol/L and -9.7%, respectively, in the patients with reduced consciousness during exercise recovery, and -2.52 micromol/L and -16.5%, respectively, in those with ventricular tachycardia. CONCLUSION: The indexes of cerebral oxygenation may drop severely enough during maximal exercise in some patients with severe IDC that consciousness is affected.

Aged↗