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 181 records · Page 10Linked to original sources
PubMed1994

Predicting recovery of severe regional ventricular dysfunction. Comparison of resting scintigraphy with 201Tl and 99mTc-sestamibi.

BACKGROUND: Regional 201Tl activity after resting injection, imaged early and after redistribution, reflects viable myocardium and can predict improved isotope uptake as well as regional and global ventricular function after revascularization. 99mTc-sestamibi, a perfusion tracer with favorable imaging characteristics, has distinct kinetics compared with 201Tl, demonstrating minimal redistribution; this property may give 201Tl an advantage for detecting viable myocardium, particularly in segments with resting hypoperfusion. The purpose of this study was to compare regional activities of 201Tl and 99mTc-sestamibi after resting injections in patients with coronary artery disease and regional or global left ventricular dysfunction and to assess their comparative abilities for predicting recovery of severe regional ventricular dysfunction after revascularization. METHODS AND RESULTS: Qualitative and quantitative comparisons of rest and redistribution 201Tl activity and sestamibi activity 1 hour after rest injection were performed in 31 patients with coronary artery disease and left ventricular dysfunction. Quantitative analysis of three short-axis tomograms per patient was performed by use of circumferential profiles that allowed analysis of 12 segments per patient. Two-dimensional echocardiography was used to assess wall motion and thickening in segments corresponding to the single photon emission computed tomography data. Concordance between regional 201Tl activity at redistribution imaging and regional sestamibi activity by semiquantitative visual analysis demonstrated concordant regional activity in 87% of segments; among discordant segments, no significant skew was seen, indicating enhanced uptake of one agent over the other. Quantitative analysis for all segments showed significant correlation (r = .86, P < .001) between quantitative regional 201Tl redistribution activity and 1-hour post-rest injection sestamibi activity in individual segments. Eighteen of these patients were revascularized, and echocardiography was repeated 20 +/- 16 days later; segments exhibiting significant regional ventricular dysfunction before revascularization were classified as having reversible or irreversible dysfunction on the basis of the change in wall motion and thickening. 201Tl and sestamibi regional activities were similar in those segments with reversible (72 +/- 11% [percent of peak activity] versus 75 +/- 9%, respectively, P = NS) as well as irreversible ventricular dysfunction (51 +/- 11% versus 50 +/- 8%, P = NS). Positive (75% versus 80% for 201Tl and sestamibi, respectively) and negative (92% versus 96%, respectively) predictive values for recovery of regional ventricular dysfunction after revascularization were similar for the two agents. CONCLUSIONS: In patients with coronary artery disease and left ventricular dysfunction, quantified sestamibi activity 1 hour after rest injection parallels redistribution 201Tl activity after a resting injection, suggesting that uptake and subsequent handling of sestamibi are more complex than can be explained by a pure flow tracer with no redistribution. Quantitative analysis of regional activities of both 201Tl and sestamibi after resting injections can differentiate viable from nonviable myocardium, and the two agents comparably predict reversibility of significant regional wall motion abnormalities after revascularization in such patients to a similar degree.

Adult↗
PubMed1998

Echocardiography and fatty acid single photon emission tomography in predicting reversibility of regional left ventricular dysfunction after coronary angioplasty.

AIMS: The present study was performed to evaluate whether echocardiographic assessment of end-diastolic wall thickness and myocardial fatty acid metabolic single-photon emission tomographic imaging with 123I-beta-methyl-iodophenyl pentadecanoic acid could be used to predict the reversibility of dysfunctional left ventricular segments after coronary artery revascularization. METHODS AND RESULTS: Twenty-eight patients with wall motion abnormalities related to stenosed coronary arteries underwent resting two-dimensional echocardiography and 123I-beta-methyl-iodophenyl pentadecanoic acid single photon emission tomography before coronary angioplasty. A dysfunctional segment was considered viable by the presence of either preserved wall thickness (> or = 75% of the thickness of a normal segment) or preserved fatty acid uptake (> or = 50% of that in normal region). Echocardiography was repeated after successful angioplasty. Functional recovery was observed in 32 (74%) of 43 hypokinetic and nine (100%) of nine akinetic segments with preserved wall thickness and in 11 (79%) of 14 thinned akinetic segments with preserved fatty acid uptake. In contrast, no functional recovery was observed in any of the 13 thinned segments with < 50% fatty acid uptake (eight akinetic and five dyskinetic). Using combined evaluation of both methods, positive and negative predictive values for post-revascularization functional outcome were 79% and 100%, respectively, in all dysfunctional segments; and 87% and 100%, respectively, in akinetic/dyskinetic segments. CONCLUSIONS: The present study showed that echocardiographic findings of preserved wall thickness and single-photon emission tomography evaluated preserved fatty acid uptake in thinned segments are reliable predictors of post-revascularization functional recovery and the concordant absence of both accurately predict negative outcome.

Adult↗
PubMed1991

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction. Comparison of thallium scintigraphy with reinjection and PET imaging with 18F-fluorodeoxyglucose.

In patients with chronic coronary artery disease and left ventricular dysfunction, the distinction between ventricular dysfunction arising from myocardial fibrosis and ischemic, but viable, myocardium has important clinical implications. By positron emission tomography (PET), enhanced fluorine-18-labeled fluorodeoxyglucose (FDG) uptake in myocardial segments with impaired function and reduced blood flow is evidence of myocardial viability. Reinjection of thallium-201 at rest immediately after stress-redistribution imaging may also provide evidence of myocardial viability by demonstrating thallium uptake in regions with apparently "irreversible" defects. To compare these two methods, we studied 16 patients with chronic coronary artery disease and left ventricular dysfunction (ejection fraction, 27 +/- 9%), all of whom had irreversible defects on standard exercise-redistribution thallium single-photon emission computed tomography (SPECT) imaging. Thallium was reinjected immediately after the redistribution study, and SPECT images were reacquired. The patients also underwent PET imaging with FDG and oxygen-15-labeled water. A total of 432 myocardial segments were analyzed from comparable transaxial tomograms, of which 166 (38%) had irreversible thallium defects on redistribution images before reinjection. FDG uptake was demonstrated in 121 (73%) of these irreversible defects. Irreversible defects were then subgrouped according to the degree of thallium activity, relative to peak activity in normal regions. Irreversible defects with only mild (60-85% of peak activity) or moderate (50-59% of peak) reduction in thallium activity were considered viable on the basis of FDG uptake in 91% and 84% of these segments, respectively. In contrast, in irreversible defects with severe reduction in thallium activity (less than 50% of peak), FDG uptake was present in 51% of segments. In such severe defects, an identical number of segments (51%) demonstrated enhanced uptake of thallium after reinjection. In these severe "irreversible" defects, data on myocardial viability were concordant by the two techniques in 88% of segments, with 45% identified as viable and 43% identified as scar on both PET and thallium reinjection studies. These observations suggest that thallium imaging can be used to identify viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction. Most irreversible defects with only mild or moderate reduction in thallium activity represent viable myocardium as confirmed by FDG uptake.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Disease↗
PubMed1993

Role of behavioral and psychological factors in mental stress-induced silent left ventricular dysfunction in coronary artery disease.

OBJECTIVES: We examined the relationship of the psychological profile to left ventricular dysfunction induced during mental stress. BACKGROUND: The contribution of psychological factors to mental stress-provoked silent myocardial ischemia has not been explored. METHODS: Thirty patients with chronic stable coronary artery disease and a reversible defect on stress thallium-201 imaging completed a psychological assessment by questionnaire and Structured Interview, serially administered mental stress and brief walking exercise. Blood pressure, electrocardiogram (ECG) and left ventricular indexes were obtained by ambulatory serial radionuclide ventriculography. Silent ventricular dysfunction was defined by a decrease > or = 0.05 in ejection fraction or > or = 1 mm in ST segment on the ECG in the absence of symptoms. RESULTS: Of the 30 patients, 15 (Group I) had evidence of silent left ventricular dysfunction during mental arithmetic. The other 15 (Group II) showed no change. In addition, 18 of 30 patients had this dysfunction during the Structured Interview. Both ischemic and nonischemic groups developed comparable and significant increases in heart rate and blood pressure. Group I patients were distinguished by higher scores on measures of aggressive responding (p < 0.001), trait anger (p < 0.0001), hostile affect (p < 0.003) and an index of behavioral reactivity (p < 0.003) and a lower score on anger control (p < 0.001). No other variables, including historical and clinical indexes, discriminated between the two groups. CONCLUSIONS: Patients with coronary artery disease and mental stress-provoked silent ventricular dysfunction were distinguished by a psychological profile consistent with emotional reactivity to social interaction and mental provocation, with anger as the predominant affective state. Patients with such a profile may be at risk of frequent silent left ventricular dysfunction.

Adult↗
PubMed1997

Increased risk of coronary artery bypass grafting for left ventricular dysfunction with dilated left ventricle.

UNLABELLED: The operative mortality and morbidity in patients with severe left ventricular dysfunction who undergo coronary artery bypass grafting (CABG) remain high. The low ejection fraction is the major risk factor for operative mortality. However, ejection fraction (EF) alone may not necessarily be an accurate predictor of operative mortality. We studied the correlation between indices of left ventricular volume and operative mortality. One thousand patients undergoing isolated coronary bypass operations were divided into three groups according to their preoperative ejection fraction. Fifty patients (group I) had severe left ventricular dysfunction (EF < or = 0.3), 56 patients (group II) had moderately left ventricular dysfunction (0.3 < EF < or = 0.4) and 894 patients (group III) had good left ventricular function (EF > 0.4). We analyzed the relationship between hospital mortality and left ventricular volume in 106 patients with an EF < or = 0.4. RESULTS: Cardiac index was not significantly different among the three groups. The left ventricular end-diastolic pressure (LVEDP) and mean pulmonary artery pressure in groups I an II were higher than those in group III. The left ventricular end-diastolic volume (LVEDV) was 146 +/- 44 ml/m2 in Group I, 112 +/- 31 ml/m2 in Group II and 82 + 30 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The left ventricular end-systolic volume (LVESV) was 111 +/- 38 ml/m2 in Group I, 72 +/- 21 ml/m2 in Group II and 30 +/- 14 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The LVEDV and LVESV were higher in Group I than in Group II and both in Groups I and II were higher than in Group III. The hospital mortality of any cause before discharge was 8.0% (4/50) in Group I, 3.6% (2/56) in Group II, and 2.0% (18/894) in Group III. The mortality in Group I was higher than that in Group III, but the mortality between Groups I and II was not different. We assessed correlations between large left ventricle with left ventricular dysfunction and operative mortality in 106 patients with ejection fractions of < or = 0.4. The hospital mortality in patients with both under fraction 0.4 and an LVESV > or = 140 ml/m2 was 50% (4/8). This rate was higher than in patients with an LVESV between 80 and 140 ml/m2 (1.8%, 1/55) (p = 0.0006) and an LVESV less than 80 ml/m2 (2.3%, 1/43), (p = 0.0013). The hospital mortality in patients with an LVEDV > or = 200 ml/m2 was 67% (4/6). It was also higher than that in patients with an LVEDV between 200 and 120 ml/m2 (1.7%, 1/58), (p = 0.0001), and an LVEDV less than 120 ml/m2 (2.4%, 1/42), (p = 0.0004). We conclude that patients with a low ejection fraction and an elevated LVESV or LVEDV are at increased risk for hospital death following CABG.

Cardiac Volume↗
PubMed1982

Normal exercise capacity in patients with severe left ventricular dysfunction: compensatory mechanisms.

About one-third of patients who have severe left ventricular dysfunction can achieve normal levels of exercise. To elucidate the mechanisms that permit this to occur, we studied six patients with severe left ventricular dysfunction (average left ventricular ejection fraction 17 +/- 2.5% [mean +/- SEM]) who achieved nearly normal levels of exercise tolerance (greater than 11 minutes of treadmill exercise, Sheffield protocol). All patients had normal pulmonary function at rest and during exercise. Hemodynamics were measured at rest and during supine and upright exercise. The major mechanisms of the preserved exercise capacity in these patients were chronotropic competence, ability to tolerate elevated wedge pressures (33 +/- 3 mm Hg) without dyspnea, ventricular dilation, and increased levels of plasma norepinephrine at rest and during exercise. Also, whereas peripheral vascular resistance was unchanged during supine exercise, it decreased by 50% during similar levels of upright exercise. As a consequence, increases in cardiac output from rest to exercise were greater during upright than supine exercise (100% vs 50%, respectively) (p less than 0.05), and pulmonary wedge pressures were lower during upright than supine exercise (21 +/- 5 mm Hg vs 33 +/- 3 mm Hg). Thus, multiple mechanisms permit some patients with severe left ventricular dysfunction to achieve normal levels of exercise. These studies emphasize that left ventricular function must be assessed by direct means rather than inferring function of the left ventricle from the results of an exercise tolerance test.

Aged↗
PubMed1994

Myocardial bioenergetic abnormalities in a canine model of left ventricular dysfunction.

OBJECTIVES: The purpose of this study was to assess high energy phosphate compound metabolism in remodeled left ventricular myocardium. BACKGROUND: The development of heart failure several years after myocardial infarction is often unexplained. Certain abnormalities of remodeled myocardium suggest that structural changes occurring in viable myocardium after discrete myocardial damage may contribute to the later appearance of heart failure. Whether these abnormalities alter metabolism in the surviving muscle and thereby possibly contribute to ventricular dysfunction is unknown. METHODS: High energy phosphate compound metabolism was assessed using spatially localized phosphorus-31 nuclear magnetic resonance spectroscopy. Eleven dogs with documented left ventricular dysfunction, resulting from infarction produced by transmyocardial direct current shock, were compared with eight normal dogs. Analyses were performed at baseline and during coronary hyperperfusion induced by intravenous adenosine. Myocardial blood flow was measured with radioactive microspheres. RESULTS: The creatine phosphate/adenosine triphosphate (CP/ATP) ratio was significantly reduced in the left ventricular dysfunction group in both the subepicardium ([mean +/- SE] 1.94 +/- 0.08 vs. 2.32 +/- 0.13, p = 0.019) and the subendocardium (1.71 +/- 0.07 vs. 2.05 +/- 0.07, p = 0.004). Intravenous adenosine produced significant coronary hyperemia in both groups but was less marked in dogs with left ventricular dysfunction. The improvement in myocardial perfusion was accompanied by a significant increase in the subendocardial CP/ATP ratio (from 1.71 +/- 0.07 to 1.92 +/- 0.08, p = 0.01) in dogs with left ventricular dysfunction. CONCLUSIONS: An abnormal transmural distribution of high energy phosphate compounds is evident in remodeled myocardium. This abnormality may be related in part to mismatch of oxygen delivery and demand.

Adenosine↗
PubMed1992

Effects of left ventricular dysfunction on the circadian variation of ventricular premature complexes in healed myocardial infarction.

Circadian variation in the onset of cardiovascular events including sudden cardiac death, myocardial infarction and ventricular arrhythmias has been described. The effect of left ventricular (LV) dysfunction on the circadian variation of ventricular premature complex (VPC) frequency was evaluated in 132 patients with frequent VPCs and reduced LV function after myocardial infarction. Patients were prospectively divided in 2 groups based on LV ejection fraction (EF) (those with LVEF less than or equal to 0.30, and those with LVEF between 0.30 and 0.45). Median hourly VPC frequencies and heart rates were compared between the 2 groups. Subgroup analyses based on treatment with beta-adrenoceptor blocking agents and on New York Heart Association functional class were also performed. In patients with LVEF greater than 0.30, a distinct circadian variation of VPCs, and the expected morning increase in VPC frequency were present. In contrast, a distinct circadian variation of VPCs was absent in patients with LVEF less than or equal to 0.30. A circadian variation of VPC frequency was also absent in patients with severe symptomatic congestive heart failure (New York Heart Association class III-IV). Treatment with beta-adrenoceptor blocking agents was associated with a loss of the circadian variation of VPC frequency. The circadian variation of heart rate was also blunted in the group treated with beta-adrenoceptor blocking agents. The proportion of subjects manifesting a positive correlation between heart rate and VPC frequency was lower in subjects with LVEF less than or equal to 0.30 (26%) than in those with LVEF greater than 0.30 (46%) (p less than 0.05). Thus, circadian variation of VPC frequency is absent in patients with severe LV dysfunction.

Adrenergic beta-Antagonists↗
PubMed2004

Optimal dosing of dobutamine for treating post-resuscitation left ventricular dysfunction.

OBJECTIVES: This study was designed to determine the optimal dose of dobutamine in the treatment of post-resuscitation left ventricular dysfunction. BACKGROUND: Global left ventricular dysfunction following successful resuscitation from prolonged, ventricular fibrillation cardiac arrest, negatively impacts long-term survival. Dobutamine can overcome this global myocardial stunning. Previous data indicate a dose of 10 mcg/kgmin improves systolic and diastolic function, but markedly increases the heart rate. METHODS: Twenty swine (24 +/- 0.4 kg) were randomized to one of four doses (0, 2, 5, and 7.5 mcg/kgmin) of dobutamine for the treatment of post-resuscitation myocardial dysfunction following 12.5 min of untreated ventricular fibrillation cardiac arrest. Cardiac function was measured at pre-arrest baseline and serially for 6 h post-resuscitation. Left ventricular function was evaluated by contrast ventriculograms, left ventricular pressures, +dP/dt, Tau, -dP/dt, and cardiac output. Myocardial oxygen consumption and myocardial blood flow were measured to assess the functional significance of any dobutamine-mediated heart rate responses. RESULTS: Left ventricular dysfunction was evident at 25 min and peaked 4 h post-resuscitation. Significant (P < 0.05) improvements in ventricular systolic (EF, CO) and diastolic (LVEDP, Tau) function were evident within minutes of dobutamine initiation and persisted at 6h for the 5 and 7.5 mcg/kgmin groups. Tachycardia manifested with all dobutamine doses, but only affected myocardial oxygen consumption significantly (P < 0.05) at the highest dose (7.5 mcg/kgmin). CONCLUSIONS: Dobutamine at 5 mcg/kgmin appears optimal for restoring systolic and diastolic function post-resuscitation without adversely affecting myocardial oxygen consumption.

Analysis of Variance↗
PubMed2000

Carbamazepine-associated severe left ventricular dysfunction.

INTRODUCTION: The cardiovascular effects of carbamazepine are well-known but left ventricular dysfunction is rarely reported. CASE REPORT: We describe 2 cases of severe carbamazepine-associated left ventricular dysfunction during massive self intoxications in young patients without preexistent cardiac disease. We compare our cases to the available literature and discuss the mechanisms implied in the development of left ventricular dysfunction following carbamazepine overdose. Bedside echocardiography was useful in both diagnosis and treatment.

Adult↗
PubMed1993

Relation between left ventricular shape and exercise capacity in patients with left ventricular dysfunction.

OBJECTIVES: The aim of this study was to identify dynamic predictors of exercise duration in patients with systolic left ventricular dysfunction and to test the hypothesis that left ventricular shape is an independent determinant of exercise duration in these patients. BACKGROUND: Measurements of left ventricular volumes and ejection fraction at rest do not predict exercise capacity in patients with systolic left ventricular dysfunction. Left ventricular shape at rest has been reported to be an independent determinant of exercise duration in these patients. The significance of alterations in left ventricular shape that occur during dynamic exercise has not been investigated. METHODS: Twenty-one patients with a documented ejection fraction < 40% performed symptom-limited graded upright bicycle exercise with simultaneous quantitative two-dimensional echocardiography. End-diastolic volume, end-systolic volume, stroke volume, ejection fraction and sphericity index were measured at rest and peak exercise. RESULTS: Eleven patients exercised beyond stage II (6 min, 50 W), averaging 8.9 +/- 1.9 min; 10 patients were unable to complete stage II, averaging 4.9 +/- 0.9 min. No patient developed clinical evidence of ischemia during the exercise period. Of the echocardiographic variables considered, only end-systolic and end-diastolic sphericity indexes at peak exercise (r = 0.809 and 0.711, respectively) and the change in end-systolic sphericity index during exercise (r = 0.697) were strongly correlated with exercise duration. CONCLUSIONS: Conventional descriptors of left ventricular function are poor predictors of exercise capacity. Dynamic changes in heart shape correlate strongly with exercise duration and may be important determinants of exercise capacity in patients with systolic left ventricular dysfunction.

Adult↗
PubMed2001

Reversibility of ventricular dysfunction. Clinical experience in a medical office.

OBJECTIVE - To describe clinical observations of marked improvement in ventricular dysfunction in a medical office environment under circumstances differing from those in study protocols and multicenter studies performed in hospital or with outpatient cohorts. METHODS - Eleven cardiac failure patients with marked ventricular dysfunction receiving treatment at a doctors office between 1994 and 1999 were studied. Their ages ranged from 20 and 66 years (mean 39.42+/-14.05 years); 7 patients were men, 4 were women. Cardiopathic etiologies were arterial hypertension in 5 patients, peripartum cardiomyopathy in 2, nondefined myocarditis in 2, and alcoholic cardiomyopathy in 4. Initial echocardiograms revealed left ventricular dilatation (average diastolic diameter, 69.45+/-8.15mm), reduced left ventricular ejection fraction (0.38+/-0.08) and left atrial dilatation (43.36+/-5.16mm). The therapeutic approach followed consisted of patient orientation, elimination of etiological or causal factors of cardiac failure, and prescription of digitalis, diuretics, and angiotensinconverting enzyme inhibitors. RESULTS - Following treatment, left ventricular ejection fraction changed to 0.63+/-0.09; left ventricular diameters changed to 57.18+/-8.13mm, and left atrium diameters changed to 37.27+/-8.05mm. Maximum improvement was noted after 16.9+/-8.63 (6 to 36) months. CONCLUSION - Patients with serious cardiac failure and ventricular dysfunction caused by hypertension, alcoholism, or myocarditis can experience marked improvement in ventricular dysfunction after undergoing appropriate therapy within the venue of the doctor's office.

Adult↗
PubMedDate not supplied

Influence of coronary artery disease and left ventricular dysfunction on postoperative mortality in vascular surgery.

In an attempt to assess the influence of coronary artery disease and left ventricular dysfunction on postoperative mortality, 107 patients consisting of 32 AAA resections and 44 aortoiliac and 31 femoropopliteal reconstructions were reviewed. All patients had a preoperative coronary angiograms and underwent cardiac catheterization to prevent cardiac-related deaths. Severe coronary artery disease was angiographically demonstrated in 40.6% of AAA, 31.8% of AI and 3.2% of FP patients. Severe left ventricular dysfunction was found in 21.9% of AAA, 18.2% of AI and 6.5% of FP. Both of the early and 5 (45.5%) of the 11 late deaths were caused by cardiac events. The nine-year survival rate (53.3%) in the patients with a documented combination of coronary artery disease and left ventricular dysfunction was significantly lower than those in patients with normal disease, normal left ventricular function and either documented coronary artery disease or left ventricular dysfunction. It is suggested from this series that left ventricular dysfunction is one of the most important risk factors in patients who undergo AAA resection and AI reconstruction and that severe disease and postoperative mortality are possibly reduced by certain kinds of interventional coronary therapies.

Actuarial Analysis↗
PubMed1980

Exercise capacity in patients with severe left ventricular dysfunction.

Normal or near-normal exercise capacity has been thought to reflect normal left ventricular function. Many compensatory mechanisms could preserve exercise capacity in patients with severe left ventricular dysfunction. We evaluated exercise capacity using a treadmill exercise test in 26 patients with severe left ventricular dysfunction defined by a left ventricular ejection fraction of 30% or less by isotope ventriculography. One half of the patients had normal exercise capacity and a normal cardiothoracic ratio on chest x-ray. This study indicates that traditional predictors of left ventricular function that have been widely used in clinical evaluation of the patients with cardiac disease (cardiothoracic ratio and exercise capacity) can be normal in a significant number of patients with severe left ventricular dysfunction. Thus, left ventricular function cannot be accurately estimated using these traditional predictors and should be assessed quantitatively. The isotope ventriculogram appears to be ideal for this purpose.

Adult↗
PubMed1995

Clinical comparison of acute single to dual chamber pacing in chronotropically incompetent patients with left ventricular dysfunction.

Dual chamber, rate responsive (DDDR) pacing is felt to be superior to ventricular, rate responsive (VVIR) pacing since it more closely mimics the normal electrical and hemodynamic activity of the heart. This reasoning has been used to justify the higher initial costs and increased complexity of dual chamber system. This study was designed to determine if objective criteria could be identified during acute testing justify implanting a dual chamber instead of a single chamber system in patients with left ventricular dysfunction. Eight patients with DDDR pacemakers (implanted for chronotropic incompetence) and left ventricular dysfunction underwent exercise radionuclide angiography and graded exercise treadmill testing. Each patient performed the tests in the single (VVIR) and dual (DDDR) chamber modes in a randomized, blinded fashion. We found that objective parameters such as ejection fraction (31% +/- 13% vs 31% +/- 10%), exercise tolerance (6.1 +/- 2.7 min vs 6.3 +/- 2.9 min), oxygen consumption (VO2) (941 +/- 286 mL/min vs 994 +/- 314 mL/min), carbon dioxide production (VCO2) (995 +/- 332 mL/min vs 1054 +/- 356 mL/min), and maximum attainable workload (43 +/- 24 W vs 46 +/- 22 W) did not differ between the single and dual chamber pacing modes. These findings suggest that in the acute setting, the additional cost and complexity of dual chamber, rate responsive pacing cannot be justified by objective improvements in exercise tolerance in patients with underlying left ventricular dysfunction.

Aged↗
PubMed2001

[Beating heart surgery and left ventricular dysfunction].

We report our experience with systematic coronary revascularization on the beating heart among patients with left ventricular dysfunction as defined by a left ventricular ejection fraction < or = 40%. Between September 1996 and April 2000, 500 off-pump (OPCAB) revascularizations were performed (95% of all revascularizations for the same time frame, single surgeon). Among them, 76 patients qualified as left ventricular dysfunction and were compared to a similar cohort of 237 patients operated on with cardiopulmonary bypass (CPB) during the same time frame. Age and sex distribution, average preoperative left ventricular ejection fraction and incidence of preoperative unstable angina were the same for both groups. On average, 3.04 +/- 0.89 and 2.97 +/- 0.69 grafts/patient were made in the OPCAB and CPB groups respectively (p = NS). Complete revascularization was achieved in 95% of the OPCAB group. Incidence of preoperative intra-aortic balloon assistance were higher in OPCAB (22% versus 9%, p = 0.005) whereas postoperative need for new intra-aortic balloon assistance was higher in CPB (8% versus 0%, p = 0.02). Incidence of postoperative myocardial infarction was comparable in both groups (6.5% versus 5.5%). Maximal creatinine phosphate of myocardial origin were lower in OPCAB group (beating heart: 32 +/- 52%, cardiopulmonary bypass: 45 +/- 51%, p = 0.055). Operative mortality was lower in OPCAB group although it did not reach statistical significance (beating heart: 2.6% versus cardiopulmonary bypass: 4.6%, p = 0.3). Complete coronary revascularization on the beating heart can be achieved in patients with left ventricular dysfunction with excellent outcome and low operative mortality.

Cardiac Surgical Procedures↗
PubMed2005

Comparison of 99mTc-sestamibi/18FDG DISA SPECT with PET for the detection of viability in patients with coronary artery disease and left ventricular dysfunction.

PURPOSE: Dual-isotope simultaneous acquisition (DISA) single-photon emission computed tomography (SPECT) is an attractive technique as it permits assessment of both myocardial glucose metabolism and perfusion within a single session, but few data on its accuracy for the assessment of viability are available as yet. In the present study, DISA SPECT was compared with positron emission tomography (PET) for the detection of myocardial viability in normal and dysfunctional left ventricular (LV) myocardium. METHODS: Fifty-eight patients with chronic coronary artery disease and LV dysfunction (LV ejection fraction 33+/-12%) were studied. Patients underwent a 1-day dipyridamole stress 99mTc-sestamibi/18F-fluorodeoxyglucose (18FDG) DISA SPECT and 13N-ammonia/18FDG PET protocol. Within 1 week, resting MRI was performed to assess contractile function. Comparison of PET and SPECT data was performed using both visual and quantitative analysis. RESULTS: The correlation of normalised activities of the flow tracers 99mTc-sestamibi and 13N-ammonia was good (r = 0.82; p < 0.001). The correlation between the two 18FDG studies was also good (r = 0.83; p < 0.001). The agreement for the assessment of viability for all segments between DISA SPECT and PET was 82%, with a kappa-statistic of 0.59 (95% CI 0.53-0.64), without a significant difference; in dysfunctional segments only, the agreement was 82%, with a kappa-statistic of 0.63 (95% CI 0.56-0.70), without a significant difference. When the DISA SPECT data were analysed visually, the agreement between DISA SPECT and PET was 83%, with a kappa-statistic of 0.58 (95% CI 0.52-0.63), without a significant difference. Moreover, there was no significant difference between visual and quantitative DISA SPECT analysis for the detection of viability. CONCLUSION: This study shows an overall good agreement between 99mTc-sestamibi/18FDG DISA SPECT and PET for the assessment of myocardial viability in patients with severe LV dysfunction. Quantitative or visual analysis of the SPECT data did not influence the agreement with PET, suggesting that visual assessment may be sufficient for clinical purposes.

Adult↗
PubMed2005

Pulmonary embolism: impact of right ventricular dysfunction.

PURPOSE OF REVIEW: The appropriate treatment of patients with acute pulmonary embolism who present with right ventricular dysfunction but normal arterial blood pressure, and particularly the potential benefits of thrombolytic treatment in this setting, continue to be highly controversial. In the past year, several well designed studies improved our understanding of subclinical right ventricular dysfunction in pulmonary embolism, and emerging risk stratification algorithms now appear to identify high-risk patients reliably. RECENT FINDINGS: A meta-analysis confirmed that echocardiographically diagnosed right ventricular dysfunction is an independent predictor of early mortality in normotensive patients with pulmonary embolism. Retrospective studies suggest that similar information can also be obtained by multidetector-row chest computed tomography. Recent data indicate that biomarker (particularly troponin) testing followed by echocardiographic imaging of the right ventricle is an efficient and reliable strategy both for excluding (ruling out) and for predicting (ruling in) a poor outcome in patients with pulmonary embolism. SUMMARY: Novel risk stratification algorithms may help identify possible candidates for early thrombolytic treatment in pulmonary embolism and thus provide the background for a large international multicenter study that will hopefully resolve the 30-year-old debate on the benefits of thrombolysis in normotensive patients with pulmonary embolism and right ventricular dysfunction.

Algorithms↗