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PubMed1987

Selective right ventricular dysfunction following doxorubicin therapy.

Cardiotoxicity is one of the major side effects of doxorubicin therapy. The side effect presents in an acute and chronic form. It has been observed mainly when the cumulative dosage exceeds 450 mg/m2 of body surface. The cardiotoxicity presents with a low left ventricular ejection fraction. We report three patients who developed selective right ventricular dysfunction, expressed by low right ventricular ejection fraction as measured by radionuclide angiography. This complication was observed with rather low cumulative dosages of the drug (105 to 318 mg/m2). Two of the patients received concurrent mitomycin-C chemotherapy and the third patient underwent prior mediastinal irradiation. The possible mechanism for this selective cardiotoxicity is discussed. Monitoring of right ventricular performance by radionuclide angiography during doxorubicin therapy is recommended so that therapy can be discontinued before the left ventricle is damaged.

Adult↗
PubMed2006

Temporal increases in subclinical levels of inflammation are associated with adverse clinical outcomes in patients with left ventricular dysfunction.

BACKGROUND: The implication of various cytokines in a subclinical inflammatory process has been documented in heart failure (HF). The role of temporal changes of more conventional markers of inflammation, such as the white blood cell (WBC) count, on clinical outcomes remains largely unknown. METHODS AND RESULTS: We performed a retrospective analysis of patients included in the Studies Of Left Ventricular Dysfunction that had documented eligibility at the baseline visit, a documented WBC count at baseline and at least 1 measurement during follow-up. We evaluated the association between variations in WBC count, WBC subfractions and mortality and non-fatal events. An increase in WBC count during follow-up compared with baseline was associated with a significantly higher risk of all-cause and cardiovascular (CV) mortality, HF mortality and arrhythmic death (all P < .05). A relative increase in the neutrophil count was associated with higher risk of all-cause and CV mortality, HF mortality and cardiac ischemic events (all P < .05). No significant interaction was present in regards to the etiology of HF. CONCLUSIONS: Temporal increases in WBC and neutrophil counts are associated with increased risks of death and CV events. This relationship appears to be independent of HF etiology.

Aged↗
PubMed1999

Dofetilide in patients with congestive heart failure and left ventricular dysfunction. Danish Investigations of Arrhythmia and Mortality on Dofetilide Study Group.

BACKGROUND: Atrial fibrillation occurs frequently in patients with congestive heart failure and commonly results in clinical deterioration and hospitalization. Sinus rhythm may be maintained with antiarrhythmic drugs, but some of these drugs increase the risk of death. METHODS: We studied 1518 patients with symptomatic congestive heart failure and severe left ventricular dysfunction at 34 Danish hospitals. We randomly assigned 762 patients to receive dofetilide, a novel class III antiarrhythmic agent, and 756 to receive placebo in a double-blind study. Treatment was initiated in the hospital and included three days of cardiac monitoring and dose adjustment. The primary end point was death from any cause. RESULTS: During a median follow-up of 18 months, 311 patients in the dofetilide group (41 percent) and 317 patients in the placebo group (42 percent) died (hazard ratio, 0.95; 95 percent confidence interval, 0.81 to 1.11). Treatment with dofetilide significantly reduced the risk of hospitalization for worsening congestive heart failure (risk ratio, 0.75; 95 percent confidence interval, 0.63 to 0.89). Dofetilide was effective in converting atrial fibrillation to sinus rhythm. After one month, 22 of 190 patients with atrial fibrillation at base line (12 percent) had sinus rhythm restored with dofetilide, as compared with only 3 of 201 patients (1 percent) given placebo. Once sinus rhythm was restored, dofetilide was significantly more effective than placebo in maintaining sinus rhythm (hazard ratio for the recurrence of atrial fibrillation, 0.35; 95 percent confidence interval, 0.22 to 0.57; P<0.001). There were 25 cases of torsade de pointes in the dofetilide group (3.3 percent) as compared with none in the placebo group. CONCLUSIONS: In patients with congestive heart failure and reduced left ventricular function, dofetilide was effective in converting atrial fibrillation, preventing its recurrence, and reducing the risk of hospitalization for worsening heart failure. Dofetilide had no effect on mortality.

Adult↗
PubMed1996

Comparison of rest thallium-201 imaging and rest technetium-99m sestamibi imaging for assessment of myocardial viability in patients with coronary artery disease and severe left ventricular dysfunction.

OBJECTIVES: We prospectively compared myocardial uptake of thallium-201 (201Tl) at rest with rest technetium-99m (99mTc) sestamibi uptake in the same patients, using quantitative singlephoton emission computed tomography (SPECT). BACKGROUND: Because of only slightly delayed redistribution, 99mTc-sestamibi uptake at rest may be less than 201Tl uptake, thereby underestimating the extent of viability. METHODS: Twenty patients (2.25 stenoses per patient) with a mean left ventricular ejection fraction of 33 +/- 2% underwent early and 3-h delayed rest 201Tl SPECT, rest 99mTc-sestamibi SPECT and two-dimensional echocardiography. RESULTS: The 280 scan segments were classified as either a normal, mild reduction in viability, defined as delayed 201Tl uptake < or = 75% and > or = 5%, or a severe reduction in viability, defined as delayed 201Tl uptake < 50%. Mild and severe defects were further classified as fixed or having rest 201Tl redistribution. Comparisons by patients were made using repeated measures analysis of variance and Dunnett's multiple comparisons test to compare 99mTc-sestamibi with initial rest 201Tl and delayed 201Tl uptake. Twenty patients had at least one mild fixed defect (95 total segments). The average percent uptake in these defects for initial 201Tl, delayed 201Tl and 99mTc-sestamibi was 62.5 +/- 2.7%, 63.1 +/- 7.1% and 67.3 +/- 9.7%, respectively (p = NS). Twelve patients (27 segments) had mild redistribution defects on serial rest 201Tl imaging. The average percent uptake was 61.6 +/- 5.2% for initial 201Tl, 67.0 +/- 9.1% for delayed 201Tl and 67.7 +/- 12.4% for 99mTc-sestamibi defects. Technetium-99m sestamibi uptake was not significantly different than that for delayed 201Tl but was significantly greater than initial 201Tl uptake. Seventeen patients (52 segments) had severe fixed 201Tl defects. The average percent uptake was 38.9 +/- 7.3% for initial 201Tl, 38.3 +/- 12.2% for delayed 201Tl and 42.7 +/- 14.2% for 99mTc-sestamibi defects in these patients (p = NS). Ten patients (19 segments) had severe redistribution defects on rest 201Tl imaging. The average percent uptake was 37.0 +/- 8.5% for initial 201Tl, 42.9 +/- 8.6% for delayed 201Tl and 44.5 +/- 11.3% for 99mTc-sestamibi defects. As was seen for mild 201Tl redistribution defects, 99mTc-sestamibi uptake was significantly higher than initial 201Tl uptake, but not significantly different than delayed 201Tl uptake in these severe defects. CONCLUSIONS: Technetium-99m sestamibi uptake after injection at rest is comparable to 201Tl uptake after injection at rest in patients with severe coronary artery disease and left ventricular dysfunction, suggesting comparable worth for viability assessment.

Cell Survival↗
PubMed1996

Baseline quality of life as a predictor of mortality and hospitalization in 5,025 patients with congestive heart failure. SOLVD Investigations. Studies of Left Ventricular Dysfunction Investigators.

This study examined the independent relation of health-related quality of life (HRQL) to mortality and congestive heart failure (CHF)-related hospitalizations in patients with an ejection fraction of < 0.35 followed for a mean of 36.5 months. A brief HRQL questionnaire was administered at baseline to patients randomized to placebo or enalapril in the Studies of Left Ventricular Dysfunction (SOLVD) trial. Participants had an ejection fraction of < 0.35 and either symptomatic CHF (treatment trial, n = 2,465) or asymptomatic CHF (prevention trial, n = 2,560). Baseline assessment of HRQL predicted mortality and CHF-related hospitalizations in symptomatic and asymptomatic patients randomized to enalapril and placebo treatment. Domains that were the stronger univariate predictors of mortality and CHF-related hospitalizations were activities of daily living (relative risk [RR] for mortality: 1.163, p < 0.000; for hospitalization: 1.215, p < 0.000), general health (RR for mortality: 1.205, p < 0.000; for hospitalization: 1.188, p < 0.000), and social functioning (RR for mortality 1.098, p < 0.000; for hospitalization: RR 1.156, p < 0.000). In the multivariate model, activities of daily living (RR for mortality 1.41, p < 0.000; for hospitalization: RR 1.43, p < 0.002), general health (RR for mortality 1.21, p < 0.000; for hospitalization RR 1.16, p < 0.013) and heart failure symptoms (RR for mortality 1.02, p < 0.025; for hospitalization RR 1.03, p < 0.004) were found to be independent risk factors. HRQL independently predicted mortality and CHF-related hospitalizations after adjustment for ejection fraction, age, treatment, and New York Heart Association classification in patients with an ejection fraction of < 0.35, randomized to enalapril and placebo treatment. HRQL provides additional clinical information regarding disease course and outcome that is not captured by traditional indexes of clinical status.

Activities of Daily Living↗
PubMedDate not supplied

B-type natriuretic peptide: practical diagnostic use for evaluating ventricular dysfunction.

Assessment of brain natriuretic peptide levels may provide important information that can be used in the evaluation of patients with dyspnea and follow-up of heart failure. Brain natriuretic peptide levels have been shown to be useful for evaluating patients in the emergency department and for evaluating patients complaining of dyspnea in the outpatient setting. Brain natriuretic peptide assessment also provides an adjunct to diagnosis of both systolic and diastolic dysfunction, has prognostic value for heart failure and in acute coronary syndromes, and may be a useful measure to guide therapy. Further work needs to be done to establish the best type of assay to use, to determine the optimal cutoff point for what is considered abnormal, and to determine how conditions other than ventricular dysfunction affect brain natriuretic peptide levels.

Acute Disease↗
PubMed1992

[The accuracy of echocardiography during the infusion of low-dose dobutamine in identifying vital myocardium in patients with obstructive coronary disease and chronic left ventricular dysfunction].

The identification of viable myocardium has important therapeutic implications in patients with coronary artery disease (CAD) and chronic left ventricular dysfunction. To assess the accuracy of transthoracic echocardiography (TTE) during dobutamine infusion for identification of viable myocardium, we have analyzed 14 patients affected by CAD and chronic abnormalities of left ventricular wall motion (RWM), present at rest, referred for coronary artery bypass grafting (CABG): 8 of 14 patients had a history of myocardial infarction with evidence of Q waves at the surface ECG. All patients had a clinical stable CAD. RWM response to dobutamine (5 mcg/kg/min and 10 mcg/kg/min) was evaluated using TTE and compared to RWM changes after CABG analyzed by intraoperative epicardial echocardiography (EE). RWM was analyzed qualitatively by dividing the left ventricle into 16 segments and a score index was assigned to each region (0: normal; 1: hypokinetic; 2: akinetic; 3: dyskinetic). Of 125 akinetic segments present at rest before CABG, 93 showed functional improvement after CABG at intraoperative EE. The RWM response to dobutamine infusion predicted intraoperative improvement after CABG in 85 of 93 segments (sensitivity: 91.3%) and identified 25 of the 32 segments which did not exhibit intraoperative improvement (specificity: 78.1%). The TTE performed 15 days after CABG showed no worsening or further improvement in RWM when compared with intraoperative EE study. Summed segment scores in 14 patients showed significantly improvement from 17.9 +/- 7, medium values at rest, to 5.1 +/- 4 after dobutamine infusion (p less than 0.001) and 5 +/- 7 after CABG (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Respiratory changes of superior vena cava flow velocity in old myocardial infarction with severe left ventricular dysfunction].

The clinical significance of the flow velocity of the superior vena cava (SVC) in old myocardial infarction (OMI) with severe left ventricular dysfunction were evaluated using pulsed Doppler echocardiography. The subjects consisted of 10 patients with OMI (averaged left ventricular ejection fraction: 0.37 +/- 0.11) and 10 age-matched normal controls. Among the patients, eight had extensive anterior infarction and two had both anterior and inferior infarctions. During normal respiration, the peak SVC flow velocities in systole (S) and diastole (D), and the D/S ratio were measured. To evaluate right ventricular diastolic function, we measured the peak velocity across the tricuspid orifice in early diastole (rapid inflow: T-R) and the atrial contraction phase (T-A), and the ratio T-A/T-R during quiet expiration. In the normal controls, S was greater than D, both during expiration and inspiration. During inspiration, S, D and the D/S in the normal controls increased, with a greater increase in D than in S. In the patients, however, D and the D/S did not increase during inspiration. T-R was less and the T-A/T-R was greater in the patients with OMI than in the normal controls. These findings of tricuspid flow velocity revealed impaired diastolic filling of the right ventricle in patients with OMI. In conclusion, the impaired diastolic filling of the right ventricle in patients with OMI might be one of the causes of the abnormal response of the SVC flow velocity during normal spontaneous respiration.

Blood Flow Velocity↗
PubMed2003

Myocardial infarction and transient ventricular dysfunction in an adolescent with sickle cell disease.

We report a case of an adolescent who had sickle cell disease and previous evidence of myocardial damage and presented with abdominal pain and rapid progression to cardiogenic shock and subsequent development of myocardial infarction. To our knowledge, this represents only the second report of a case of acute myocardial ischemia and subsequent infarction resulting transient ventricular dysfunction reported in a child with sickle cell disease successfully treated with exchange transfusion. The pathophysiology of this complication remains unclear, and cardiac complications may remain undetected as lung, bone, and brain infarcts are more common and the pain associated with sickle cell crisis may mask the ischemic symptoms. Multiple factors may contribute to ischemia in addition to the presence of a vaso-occlusive crisis or infection. Acute or chronic myocardial ischemia are probably more prevalent than currently known.

Acute Disease↗
PubMed2006

Improved survival with drug-eluting stent implantation in comparison with bare metal stent in patients with severe left ventricular dysfunction.

OBJECTIVE: We examined the efficacy of drug-eluting stent (DES) implantation (Sirolimus or Paclitaxel) in patients with ischemic cardiomyopathy and severe left ventricular (LV) dysfunction and compared the outcome with a similar group of patients undergoing bare metal stent (BMS) implantation. BACKGROUND: Patients with severe LV dysfunction are a high risk group. DES may improve the long term outcomes compared with BMS. METHODS: One hundred and ninety one patients (23% women) with severe LV dysfunction (LV ejection fraction < or =35%) underwent coronary stent implantation between May 2002 and May 2005 and were available for follow-up. One hundred and twenty eight patients received DES (Sirolimus in 72 and Paclitaxel in 54) and 63 patients had BMS. Patients with acute S-T elevation myocardial infarction (STEMI) were excluded. The primary endpoint was cardiovascular mortality. A composite endpoint of major adverse cardiac events (MACE) including cardiovascular mortality, myocardial infarction (MI), and target vessel revascularization (TVR) was the secondary endpoint. RESULTS: Mean follow-up was 420 +/- 271 days. No differences were noted in age (69 +/- 10 years vs. 70 +/- 10 years, P = NS), number of vessel disease (2.3 +/- 0.7 vs. 2.2 +/- 0.8, P = NS), history of congestive heart failure (47% vs. 46%, P = NS), MI (60% vs. 61%, P = NS), or number of treated vessels (1.3 +/- 0.5 vs. 1.3 +/- 0.6, P = NS) for the DES and BMS group, respectively. Diabetes was more common among DES patients (45% vs. 25%, P = 0.01). The left ventricular ejection fraction (LVEF) was similar between the two groups (28% +/- 6% vs. 26% +/- 8%, P = NS for the DES and BMS, respectively). During the follow-up, there were a total of 25 deaths of which two were cancer related (2 in DES group). There were 23 cardiac deaths, 8/126 (6%) which occurred in the DES group and 15/63 (24%) in the BMS group (P = 0.05 by log-rank test). MACE rate was 10% for the DES group and 41% for the BMS group (P = 0.003). NYHA class improved in both groups (from 2.5 +/- 0.8 to 1.7 +/- 0.8 in DES and from 2 +/- 0.8 to 1.4 +/- 0.7 in the BMS, P = NS). CONCLUSION: Compared with bare-metal stents, DES implantation reduces mortality and MACE in high risk patients with severe left ventricular dysfunction.

Aged↗
PubMed1997

[The effect of left ventricular dysfunction on nocturnal desaturation in patients with chronic emphysematous bronchitis and PaO2 55-70 mmHg].

The possibility of nocturnal oxygen desaturation (NOD) in patients with chronic bronchitis and emphysema (CBE) even with basal hypoxemia greater that 55 mmHg is well recognised. Nocturnal hypoventilation is admitted as the main cause for this NOD. In this study we evaluate how the presence of left ventricular dysfunction (LVD) could aggravate NOD. Thirty-six patients with CBE and basal stabilised PaO2 55-70 mmHg underwent right heart catheterisation and polysomnographic study. NOD was defined as more than 30% of total sleep time with SaO2 less than 90%; LVD was defined as capillary pressure greater than 15 mmHg. Six patients were excluded from analysis because of sleep apnoea syndrome. In the remaining 30 patients (20 men, 10 women; mean age = 65.88.6 years; mean FEV1 = 0.970.31 litres; 43.316.6% predicted; mean basal PaO2 = 61.83.6 mmHg) 8 had LVD and 18 and NOD. Patients with NOD had a greater diurnal level of hypoventilation (basal PaCO2 = 44.63.8 vs. 414.1 mmHg; p = 0.025). Patients with LVD, despite identical diurnal pulmonary function, showed a significantly p < 0.05) greater degree of NOD (mean nocturnal SaO2 = 84.56.4 vs 89.52.5; minimal nocturnal SaO2= 68.517.3 vs. 79.47.8; Time spent with SaO2 < 90% = 78.833.7 vs. 43.138.7). We conclude that the presence of LVD in patients with CBE and PaO2 55-70 mmHg aggravates the intensity and the time spent with NOD, probably because of aggravation of hypoventilation or ventilation/perfusion mismatching.

Aged↗
PubMed1999

99mTc-tetrofosmin SPECT for prediction of functional recovery defined by MRI in patients with severe left ventricular dysfunction: additional value of gated SPECT.

UNLABELLED: This study was designed to evaluate gated 99mTc-tetrofosmin SPECT for prediction of functional recovery proven by sequential MRI. 99mTc-labeled tetrofosmin is a recently introduced tracer for myocardial perfusion. However, its role for viability assessment is still under investigation. METHODS: 99mTc-tetrofosmin uptake in 19 patients with coronary artery disease and severe left ventricular dysfunction was correlated to regional wall thickening before and 4.5 +/- 0.8 mo after successful coronary artery bypass grafting, as derived from corresponding gated short-axis MRI. Preoperative wall thickening determined by gated SPECT was used as an additional parameter for prediction of functional outcome. Optimal threshold cutoffs to separate reversible from irreversible dysfunction were determined by receiver operator characteristic (ROC) analysis. RESULTS: The sensitivity and specificity of regional 99mTc-tetrofosmin for prediction of functional recovery was 87% and 42%, respectively (cutoff: 50% of maximum tracer retention). The area under ROC curves for prediction of functional recovery measured 0.66 +/- 0.01. Segments with > or =50% uptake and impaired but detectable wall thickening determined by gated SPECT had a significantly higher likelihood for functional improvement compared with segments with absent wall thickening (P < 0.05). There was no difference in segments with <50% tracer retention. There was good agreement for ejection fraction measurements by MRI and gated SPECT (mean ejection fraction 32 +/- 12 versus 34 +/- 11; r = 0.71, P < 0.001). CONCLUSION: Regional 99mTc-tetrofosmin uptake provided high sensitivity but limited specificity for prediction of functional recovery after revascularization, leading to fair overall accuracy. Wall thickening assessment derived from gated SPECT may improve the specificity of 99mTc-tetrofosmin uptake for prediction of functional recovery but not the sensitivity in low-flow areas. In addition to the assessment of global function, gated data acquisition can be helpful to improve the overall accuracy of 99mTc-tetrofosmin SPECT for prediction of functional recovery after bypass surgery.

Coronary Artery Bypass↗
PubMed2002

CD14-deficient mice are protected against lipopolysaccharide-induced cardiac inflammation and left ventricular dysfunction.

BACKGROUND: The molecular mechanisms responsible for sepsis-induced myocardial dysfunction remain undefined. CD14 mediates the inflammatory response to lipopolysaccharide (LPS) in various organs including the heart. In this study we investigated the role of CD14 in LPS-induced myocardial dysfunction in vivo. METHODS AND RESULTS: Wild-type and CD14-deficient (CD14-D) mice were challenged with Escherichia coli LPS. Myocardial tumor necrosis factor, interleukin-1beta (IL-1beta), and NOS2 induction was measured before and 6 hours after LPS challenge. Echocardiographic parameters of left ventricular function were measured before and 6 hours after LPS administration. LPS challenge induced a significant increase in myocardial tumor necrosis factor and IL-1beta mRNA and protein expression in wild-type mice. In contrast, mRNA and protein levels for TNF and IL-1beta were significantly blunted in CD14-D mice. An increase in NOS2 protein was noted within 6 hours of LPS provocation only in the hearts of wild-type mice. This was associated with an increase in ventricular cGMP levels. Activation of nuclear factor-kappaB was observed within 30 minutes of LPS in the hearts of wild-type mice but not in CD14-D mice. In wild-type mice, LPS significantly decreased left ventricular fractional shortening, velocity of circumferential shortening, and dP/dt(max). LPS-treated CD14-D mice maintained normal cardiac function. CONCLUSIONS: These results suggest that CD14 is important in mediating the proinflammatory response induced by LPS in the heart and that CD14 is necessary for the development of left ventricular dysfunction during LPS-induced shock in vivo.

Animals↗
PubMed2004

Effect of ramipril in reducing sudden deaths and nonfatal cardiac arrests in high-risk individuals without heart failure or left ventricular dysfunction.

BACKGROUND: ACE inhibitor therapy reduces the risk of cardiovascular death, myocardial infarction, stroke, hospitalization for heart failure, and need for revascularization in high-risk patients with clinical heart failure, overt left ventricular systolic dysfunction, or vascular disease. In patients with clinical heart failure or overt left ventricular systolic dysfunction, ACE inhibitor therapy also reduces the risk of sudden or arrhythmia-related cardiac death. The objective of this study was to assess the effect of the ACE inhibitor ramipril on sudden unexpected death or resuscitated cardiac arrest among the 9297 individuals without clinical heart failure or overt left ventricular dysfunction enrolled in the Heart Outcomes Prevention Evaluation (HOPE) trial. METHODS AND RESULTS: During the median follow-up of 4.5 years, the composite outcome of unexpected death, documented arrhythmic death, or resuscitated cardiac arrest was reduced by 21% in patients randomized to ramipril therapy compared with those randomized to placebo. There were 155 (3.3%) composite outcome events in patients randomized to ramipril therapy compared with 195 (4.2%) such events in patients randomized to placebo (RR 0.79, 95% CI 0.64 to 0.98, P=0.028). There were trends toward reductions in fatal primary outcome events (unexpected death or documented arrhythmic death; RR 0.81, 95% CI 0.64 to 1.02, P=0.072) and in nonfatal primary outcome events (resuscitated cardiac arrest; RR 0.65, 95% CI 0.38 to 1.13, P=0.127) in the ramipril treatment group. CONCLUSIONS: Ramipril reduces the risk of fatal and nonfatal serious arrhythmic events in high-risk patients without clinical heart failure or overt left ventricular systolic dysfunction.

Aged↗
PubMed1997

Potassium channel opener-augmented cardioplegia: protection of myocyte contractility with chronic left ventricular dysfunction.

BACKGROUND: An increased number of patients with preexisting left ventricular (LV) dysfunction and congestive heart failure (CHF) are undergoing cardiac surgery with a higher risk for decreased LV contractility after hyperkalemic cardioplegic arrest. Activation of adenosine triphosphate-sensitive potassium channels by potassium channel openers (PCO) within the myocyte appears to confer a protective effect in the setting of ischemia. Accordingly, the present study was designed to determine whether PCO supplementation during hyperkalemic cardioplegic arrest would provide protective effects on myocyte contractile function, particularly in the setting of CHF. METHODS AND RESULTS: LV myocytes were isolated from control pigs (n=7) and pigs with CHF (rapid pacing, 240 beats per minute; n=7) and then assigned to the following treatment groups: normothermia (cell culture media, 2 hours, 37 degrees C); cardioplegia (24 mEq/L K+, 2 hours, 4 degrees C; then 10 minutes of reperfusion); or PCO/cardioplegia (cardioplegia supplemented with 100 micromol/L of the PCO aprikalim). Myocyte velocity of shortening was reduced in both control (66+/-2 versus 33+/-1 microm/s) and CHFmyocytes (32+/-1 versus 22+/-1 microm/s) after hyperkalemic cardioplegic arrest (P<.05). Contractility after PCO cardioplegia was similar to normothermic values in control (57+/-2 microm/s) and CHF (33+/-1 microm/s) myocytes (P<.05). Intracellular free Ca2+ increased from normothermia during hyperkalemic cardioplegia in control (81+/-4 to 145+/-7 nmol/L) and CHF (262+/-30 to 823+/-55 nmol/L) myocytes (P<.05). PCO cardioplegia attenuated the intracellular increase in free Ca2+ during the cardioplegic interval in control (110+/-6 nmol/L) and CHF (383+22 nmol/L) myocytes (P<.05). CONCLUSIONS: PCO-augmented cardioplegic arrest preserved myocyte contractility and reduced the intracellular free Ca2+ release, which therefore may be of particular benefit in the setting of preexisting LV dysfunction.

Animals↗
PubMed1995

Transition from asymptomatic left ventricular dysfunction to congestive heart failure.

One of the main goals of modern management and care of heart failure is to prevent the disease to progress toward congestion and death. The achievement of such an objective may, in fact, guarantee a sufficient quality of life and reduce the exposure of patients to the most common life-threatening complications associated with the congestive stage of the disease. Early identification of left ventricular dysfunction as well as a better knowledge of the mechanisms that favor the progression to more advanced stages of heart failure are fundamental requirements for the proper treatment of asymptomatic heart failure and for preventing the transition to symptomatic and more severe heart failure. The authors reviewed the literature on this topic, with emphasis on a series of studies they performed, to characterize the pathophysiologic profile of mild heart failure and the mechanisms that are possibly involved in the progression to congestive heart failure.

Adaptation, Physiological↗
PubMed2006

"Indeterminate" microvolt T-wave alternans tests predict high risk of death or sustained ventricular arrhythmias in patients with left ventricular dysfunction.

OBJECTIVES: This study tested the hypothesis that an "indeterminate" microvolt T-wave alternans (MTWA) test, when due to ectopy, unsustained MTWA, or low exercise heart rate (HR), has prognostic significance similar to a positive MTWA test. BACKGROUND: MTWA testing, used to stratify risk of sudden or total mortality in patients with structural heart disease, has been limited by a substantial number of "indeterminate" tests. Indeterminate tests are due to patient factors--excessive ventricular ectopy during exercise, unsustained MTWA, or failure to achieve a HR of 105 beats/min for 1 min--or technical factors such as a noisy recording or an exercise protocol that causes an excessively rapid rise in HR. METHODS: Patients in sinus rhythm with left ventricular ejection fraction < or =0.40 underwent MTWA exercise tests, analyzed with the spectral method and classified by a computerized interpretation algorithm. The primary end point was all-cause mortality or documented non-fatal sustained ventricular arrhythmia (SVA). "Indeterminate" tests were reviewed jointly by 2 readers blinded to subsequent events to determine the primary reason for indeterminacy. RESULTS: Participants (N = 549) were 56 +/- 13 years and 71% male; 49% had ischemic cardiomyopathy. There were 40 deaths and 11 non-fatal SVA. Most (94%) indeterminate results were due to patient factors. The 2-year rate for death or SVA was 17.8% in patients with an "indeterminate" MTWA test compared with 12.3% in those with a positive test. CONCLUSIONS: In patients with left ventricular dysfunction, an "indeterminate" MTWA test due to patient factors predicted death or SVA at least as well as a positive test.

Adult↗
PubMed2005

Assessment of coronary microcirculation in patients with takotsubo-like left ventricular dysfunction.

BACKGROUND: The precise mechanism of takotsubo-like left ventricular (LV) dysfunction remains unclear. METHODS AND RESULTS: Eight consecutive patients with takotsubo-like LV dysfunction were studied. In the acute phase and 3 weeks later, the coronary flow velocity spectrum and coronary flow velocity reserve (CFVR) were recorded by Doppler guidewire. The deceleration time of diastolic velocity (DDT; ms) was measured from the peak diastolic velocity to the point where the extrapolated line intersected the baseline. In all cases, CFVR of the 3 coronary arteries increased during follow-up (1.7+/-0.5 to 2.4+/-0.5 for the left anterior descending artery (p < 0.05), 1.7+/-0.5 to 2.7+/-0.8 for the left circumflex artery (p < 0.05) and 1.7+/-0.3 to 2.5+/-0.4 for the right coronary artery (p < 0.05)). In addition, the DDT of all coronary arteries increased during follow-up. CONCLUSIONS: Decreased CFVR and short DDT were demonstrated in patients with takotsubo-like transient LV dysfunction in the acute phase, and these findings improved 3 weeks later, which suggests that coronary microvascular dysfunction may be a causative mechanism.

Aged↗