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PubMedDate not supplied

Low incidence of neoplasia in heart and heart-lung transplant recipients receiving triple-drug immunosuppression.

The risk of neoplasias developing after solid organ transplantation is markedly increased by immunosuppressive therapy. Lymphoma has been reported to develop in 13% of heart and in 33% of heart-lung transplant recipients treated with cyclosporine, and the incidence of skin carcinoma ranges between 6% and 16%. The incidence of posttransplant neoplasias with the use of lower loading and maintenance doses of cyclosporine as used in triple-drug immunosuppression is unknown. From December 1983 through August 1988, 134 heart and seven heart-lung transplants were performed at the University of Minnesota. All patients received a combination of cyclosporine, azathioprine, and prednisone. Survival was 94% at 1 and 90% at 3 years in heart recipients. Probability of acute rejection was 9% at 3 months and 12% at 1 and 3 years. B-cell lymphoma developed after heart transplant in only two patients for an incidence of 1.5%. Episodes of acute rejection and mean cyclosporine blood level did not predict the occurrence of posttransplant lymphoma. The incidence of skin carcinoma was 6.4%. No neoplasia occurred in heart-lung transplant recipients. All neoplasias were observed in patients older than 50 years. Our data indicate that the risk for developing lymphoproliferative disorders, but not for basal cell carcinoma, is reduced in heart and heart-lung transplant recipients receiving triple-drug immunosuppression. Older recipients may be at increased risk, suggesting that lower doses of immunosuppressive therapy should be considered in this group.

Azathioprine↗
PubMed1989

Influence of ibopamine on heart rate and arrhythmic pattern in patients with congestive heart failure. A double-blind multicentre study.

Ibopamine is a dopaminergic and adrenergic receptor agonist, which is active in the treatment of congestive heart failure. Since the long-term prognosis for patients with congestive heart failure remains very poor and the incidence of arrhythmic death is high, every new drug to be employed against this disease should be thoroughly tested in order to rule out any possible arrhythmogenic action. This multicentre study was designed to evaluate the effect of ibopamine versus placebo in double-blind conditions on heart rate, rhythm and electrical safety. Ibopamine was employed at a dose of 100 mg t.i.d. in 97 patients (aged 31-83 years) belonging to NYHA class II and III with congestive heart failure of different aetiology, but without any complex ventricular arrhythmias in basal conditions (couplets with R'-R" less than or equal to 400 msec, ventricular tachycardia, R on T phenomena). Using a random cross-over design the patients were submitted to 48 hr. Holter recordings in basal conditions and following 7 days of ibopamine and placebo treatment. No influence on heart rhythm was noted. No significant variations in maximum heart rate (ibopamine 117.7 +/- 20.9; placebo 118.1 +/- 20.7), medium heart rate (ibopamine 71.8 +/- 10.2; placebo 72.6 +/- 10.1) or minimum heart rate (ibopamine 55.3 +/- 11.7; placebo 54.6 +/- 10.6) were observed. The mean number/hr. of ectopic supraventricular beats was 26.1 +/- 61.9 after ibopamine and 21.7 +/- 35.8 after placebo (p = ns). The complexity of ectopic supraventricular beats did not change. The mean number/hr. of ectopic ventricular beats was 31.1 +/- 52.5 after ibopamine and 30.4 +/- 57.8 after placebo (p = ns). Neither the distribution of the patients among Lown classification nor the Final Score of the Italian Lown Classification (26.1 +/- 18.0 and 26.6 +/- 17.9 in the 1st and 2nd day of monitoring after ibopamine and 25.7 +/- 18.6 and 25.7 +/- 18.8 after placebo; p = ns) showed any difference between active treatment and placebo. Similar results were achieved when the patients were sub-divided into subgroups according to sequences of treatment (basal----ibopamine----placebo and basal----placebo----ibopamine), NYHA class II or III, aetiology of congestive heart failure (dilatative cardiomyopathy, ischemic cardiomyopathy and other aetiologies), associated treatment with digitalis or diuretics and the number and complexity of base ectopic ventricular beats. None of the patients experienced sustained ventricular tachycardia.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1982

Postnatal changes of the tonic influence of the vagus nerves on the heart rate, and of the activity of choline acetyltransferase in the heart atria of rats.

Postnatal changes in the resting heart rate and in its parasympathetic tonic inhibition have been measured in awake rats and compared with changes in the activity of choline acetyltransferase (ChAT) in the heart atria. The heart rate at rest increased from 372.min-1 on the 1st to 456 and 442.min-1 on the 15th and 24th day of life and then again decreased to 358 and 356.min-1 in 60-day-old and adult rats. Until the 15th day of postnatal life, the administration of atropine did not bring about an increase in the heart rate; the cardio-acceleratory effect of atropine (indicating the presence of tonic vagal inhibition of the heart) appeared only on the 18th day and increased steeply up to the 40th day of postnatal life. The activity of ChAT in the heart atria was measured as the difference between the synthesis of acetylcholine in atrial homogenates incubated in the absence and in the presence of bromoacetylcholine (BrACh), a specific inhibitor of ChAT; this procedure eliminated the contribution of carnitine acetyltransferase to the synthesis of acetylcholine. The activity of ChAT was found to increase steeply from the 1st to the 25th days of postnatal life; the steepest increase in the activity of the enzyme occurred between the 4th and the 15th days. Temporal correlation between the changes in the activity of ChAT, in the content of acetylcholine in the heart atria (Kuntscherová and Vlk 1979) and in the efficiency of transmural stimulation of sinoatrial region on the heart rate (Vlk 1979) indicate that the functional maturation of intracardiac cholinergic neurones, proceeding in rats during the first three weeks of their postnatal life, plays an important role in the onset and temporal development of the tonic parasympathetic inhibition of the heart rate.

Acetylcholine↗
PubMed1994

Adult orthotopic heart transplantation using undersized pediatric donor hearts. Technique and postoperative management.

BACKGROUND: Because of the critical shortage of adult donor hearts, many recipients die awaiting transplantation of an organ of appropriate size. Undersized hearts (donor/recipient weight ratio < 0.7) have been used for heterotopic heart transplantation. We report on 6 moribund adult heart transplant candidates who were rescued with orthotopic heart transplantation of undersized pediatric hearts. METHODS AND RESULTS: Recipients were hypotensive (mean blood pressure, 62.3 +/- 13.4 mm Hg), had high pulmonary artery pressures (mean pulmonary artery pressure, 42.4 +/- 6.3 mm Hg), and had mean cardiac indexes of 1.7 +/- 0.6 L.min-1.m-2. Four had pretransplant intra-aortic balloon pumps, and one was on a Thoratec left ventricular assist device complicated by fungemia. Since conventionally sized donors were unavailable (+/- 30% recipient weight), the patients were listed in a wider weight range (+/- 60%). Donor characteristics were age, 8.7 +/- 1.5 years; weight, 32.8 +/- 7.0 kg; and donor/recipient weight ratio, 0.44 +/- 0.2, with average ischemic time of 236.0 +/- 59.3 minutes. Technical considerations during transplantation included (1) opening the donor right atrium from the inferior vena cava to superior vena cava to facilitate size matching, (2) performing size-mismatched pulmonary artery and aortic anastomoses end to end, (3) infusing prostaglandin E1 12 ng.kg-1.min-1 to decrease pulmonary and systemic vascular resistance, (4) pacing donor and recipient atria synchronously to improve ventricular filling, (5) maintaining high heart rates up to 140 beats per minute (initially with isoproterenol or pacing, chronically with theophylline), (6) hyperventilating with sedation and paralysis as necessary, (7) reperfusing with triiodothyronine, and (8) minimizing afterload. All patients were discharged from the hospital. At 1 week, hemodynamics were normal and echocardiograms demonstrated left ventricular growth. CONCLUSIONS: Hence, undersized pediatric hearts can be used successfully to salvage moribund patients and expand the potential donor pool for adult orthotopic heart transplantation.

Body Constitution↗
PubMedDate not supplied

Influence of heart transplantation on the natural history of patients with severe congestive heart failure.

In an attempt to study the influence of heart transplantation on the natural history of patients with severe congestive heart failure, we have reviewed our experience with 240 consecutive patients who were New York Heart Association class IV or III/IV, who had left ventricular ejection fraction less than 35%, who were younger than 65 years of age, and who were assessed for heart transplantation in our hospital since May 1986. Mean age was 47 +/- 12 years. Left ventricular ejection fraction was 20% +/- 6%. Eighty-seven percent were male. New York Heart Association class was IV in 88% and III/IV in 12%. The cause was ischemic heart disease in 35% of patients, valvular heart disease in 13% of patients, and primary dilated cardiomyopathy in 52% of patients. At initial assessment, heart transplantation was considered to be not indicated in 30% of patients, indicated in 51% of patients, and contraindicated in 19% of patients. During a follow-up of 13 +/- 13 months (2 to 64 months), 110 patients underwent transplantation (46%). Posttransplantation actuarial probability of survival was 70% at 3 years. Three-year probability of survival free from transplantation was significantly lower for patients older than 55 years of age (p < 0.05), for those with left ventricular ejection fraction less than 20% (p < 0.05), ischemic causes (p < 0.05), New York Heart Association class IV (p < 0.001), and indication/contraindication for transplantation (p < 0.001); no difference was noted for gender.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1997

Heart muscle and plasma vitamin Q with heart transplantation.

OBJECTIVE: To study variations in heart muscle septum and plasma vitamin Q (Q, ubiquinone, n = 9) and plasma vitamin E (E, alpha-tocopherol, n = 4) in heart transplant patients. DESIGN: Right-sided heart septum biopsies and plasma samples were routinely saved in patients (eight males and one female, aged 48 +/- 6 years [mean +/- SEM], range 19 to 58). Observation time was one to 35 months involving one to 10 examinations. RESULTS: Average heart and plasma Q were 0.33 +/- 0.04 mg/g, range 0.06 to 0.58, and 0.65 +/- 0.10 mg/L, range 0.20 to 1.08, respectively. Corresponding values for those with only plasma E analyzed were 0.39 +/- 0.03 mg/g and 0.70 +/- 0.10 mg/L, respectively. Plasma E averaged 7.7 +/- 1.7 mg/L, range 4.6 to 11.3. There were no differences between patients in stable condition and healthy persons in heart and plasma Q, whereas plasma E corresponded to only 64% of the mean in healthy persons. On an individual level a relationship was present between heart and plasma Q. For high plasma Q, heart Q appeared to be saturated. In four patients, from whom plasma samples were taken close to a fatal complication, plasma Q averaged 0.42 mg/L (P < 0.01). CONCLUSIONS: Well controlled heart transplant patients had normal heart and plasma Q, whereas plasma E was depressed. Muscle and plasma Q became depressed, particularly with rejection episodes and/or infections.

Adult↗
PubMed1998

[Evaluation of therapy for dilated cardiomyopathy with heart failure by iodine-123 metaiodobenzylguanidine imaging: comparison with heart rate variability power spectral analysis].

The relationship between the myocardial uptake of iodine-123 metaiodobenzylguanidine (123I-MIBG) and heart rate variability parameters has not been determined. This study determined the relationship between the change in myocardial uptake of 123I-MIBG and improvement in left ventricular function after treatment, to determine the usefulness of 123I-MIBG imaging to assess the effect of therapy on heart failure due to dilated cardiomyopathy (DCM). 123I-MIBG imaging and power spectral analysis of heart rate variability were performed before and after treatment in 17 patients with heart failure due to DCM. The following parameters were compared before and after treatment: New York Heart Association (NYHA) functional class, radiographic cardiothoracic ratio (CTR), blood pressure, echocardiographic data [left ventricular end-systolic (LVDs) and end-diastolic (LVDd) diameters, left ventricular ejection fraction (LVEF)], plasma concentrations of norepinephrine and epinephrine, heart rate variability power spectral analysis data [mean low frequency (MLF) and high frequency power (MHF)] and the myocardium to mediastinum activity ratio (MYO/M) obtained in early and late images, and washout rate calculated by anterior planar imaging of 123I-MIBG. The NYHA functional class, LVEF, LVDs, CTR, MLF and MHF improved after treatment. Early MYO/M and late MYO/M improved after treatment. The rate of increase in late MYO/M was positively correlated with the rate of improvement of LVEF after treatment. Furthermore, the late MYO/M was negatively correlated with MLF. Washout rate revealed no correlation with hemodynamic parameters. These findings suggest that late MYO/M is more useful than washout rate to assess the effect of treatment on heart failure due to DCM. Furthermore, the 123I-MIBG imaging and heart rate variability parameters are useful to assess the autonomic tone in DCM with heart failure.

3-Iodobenzylguanidine↗
PubMed1992

Heart, heart-lung, and lung transplantation in the first year of life.

Seventeen infants less than 1 year of age have undergone heart (12), heart-lung (3), and lung (2) transplantation for end-stage cardiopulmonary disease. The infants undergoing heart transplantation had a mean age of 4.5 months (range, 19 days to 12 months) with the diagnosis of cardiomyopathy in 4 and congenital heart disease in 8. Four of the 8 patients (50%) had hypoplastic left heart syndrome. Actuarial survival at 1 and 2 years was 74% and compared favorably with the survival of older children at 1 and 2 years of 82% and 69%. The linearized rejection rate was less in infants as compared with children more than 1 year of age (0.61 versus 1.48 episodes per 100 patient days). In intermediate follow-up, no graft atherosclerosis has been noted. Immunosuppression has included a three-drug protocol of cyclosporine, azathioprine, and prednisone. A steroid taper to alternate day steroids or off completely by 6 months has been the goal and has been accomplished in 6 of 12 infants. Heart-lung and lung transplantation has been performed in 5 infants. One infant in each group died: 1 infant secondary to airway complications and sepsis and another due to pulmonary sepsis. A pulmonary lobe from a larger and older donor was transplanted into a 4-week-old infant as a single-lung transplant with good outcome. The 3 surviving infants are well 24, 18, and 2 months after transplantation. Obliterative bronchiolitis has not been clinically apparent in this group. These data support the clinical efficacy of heart, heart-lung, and lung transplantation in the first year of life.

Actuarial Analysis↗
PubMed2001

Molecular characterization of the ventricular conduction system in the developing mouse heart: topographical correlation in normal and congenitally malformed hearts.

OBJECTIVES: Within the adult heart, it is convention to distinguish the conduction system and working (atrial and ventricular) myocardium. The adult conduction system (CS) comprises the sinoatrial (SAN), and atrioventricular (AVN) nodes, the atrioventricular bundle (AVB), the bundle branches and the peripheral Purkinje fibers, each of which display distinct functional properties and distinct profile of gene expression. Characterization of the mouse cardiac conduction system during development is rudimentary at present, even though genetically-modified mice are an increasing source of information regarding cardiac function and embryonic heart development. METHODS: We have performed a detailed study of the pattern of expression of myosin heavy chain (MHC), myosin light chain (MLC), troponin I (TnI) isoforms, connexin 43 (Cx43), desmin and alpha-smooth muscle actin (alpha-SMA), in the ventricular conduction system of normal and congenitally malformed mouse hearts (iv background) from embryonic day 14.5 to 19.5. RESULTS: The AVN is characterized by co-expression of MHC and MLC isoforms and no detectable expression of Cx43, desmin or alpha-SMA. The AVB expresses betaMHC and MLC2v, but no alphaMHC, MLC2a, Cx43, desmin or alpha-SMA. The right and left bundle branches display enhanced expression of desmin and alpha-SMA but no Cx43. The normal expression profile is maintained in congenitally malformed hearts such as double-outlet right ventricle and common atrioventricular canal. Three-dimensional reconstruction of the conduction system shows normal arrangement of the bundle branches in congenitally malformed hearts, but abnormal location and/or extension of the AVN. CONCLUSIONS: Molecular characterization allows to follow the development of the CS in both, normal and malformed mouse hearts. Normal phenotypic expression of the CS is independent of heart situs but shows minor modifications in the presence of heart malformations. It is concluded that the AVN derives from the atrioventricular canal myocardium, the bundle of His from the ventricular myocardium, and the bundle branches from the ventricular trabeculations. Our results do not provide evidence to support an extra-cardiac origin of the ventricular CS.

Actins↗
PubMed1999

Exposure of circumflex branches in the tilted, beating porcine heart: echocardiographic evidence of right ventricular deformation and the effect of right or left heart bypass.

OBJECTIVE: In off-pump coronary surgery, exposure of posterior vessels via sternotomy causes deterioration of cardiac function. Changes in ventricular geometry, valve competence, and hemodynamics after retraction of the beating heart were studied. Subsequently, the modifying effect of right or left heart bypass was investigated. METHODS: In six 80-kg pigs, an ultrasound probe was attached to the backside of the left ventricle and the heart was fully retracted with a suction tissue stabilizer. Five pigs underwent additional pump support. RESULTS: During retraction, the right ventricle was squeezed between the pericardium and interventricular septum, thereby decreasing its diastolic cross-sectional area by 62% +/- 6% (P <.001) while, concomitantly, right ventricular end-diastolic pressure increased to 165% +/- 19% (P =.004) of basal values. Stroke volume and mean arterial pressure decreased by 29% +/- 6% and 23% +/- 8% (P =.007 and P =.02, respectively). Left ventricular shape became somewhat elliptic without changes in preload pressure, and its diastolic cross-sectional area decreased by 20% +/- 3% (P =.001). All valves were competent. Right heart bypass restored left ventricular cross-sectional area, stroke volume, and mean arterial pressure. In contrast, left heart bypass increased blood pressure only marginally. CONCLUSIONS: Ninety-degree anterior displacement of the beating porcine heart caused primarily right ventricular dysfunction as a result of mechanical interference with diastolic expansion without concurring valvular incompetence. Right heart bypass normalized stroke volume and mean arterial pressure by increasing left ventricular preload; in contrast, left heart bypass failed to restore systemic circulation.

Animals↗
PubMedDate not supplied

Management of heart failure. IV. Anticoagulation for patients with heart failure due to left ventricular systolic dysfunction.

OBJECTIVE: This article reviews the incidence of arterial thromboembolism in patients with heart failure who are not receiving anticoagulants. We also examine whether more severe ventricular dysfunction increases this incidence and the efficacy and risks of anticoagulation for patients in sinus rhythm. DATA SOURCES: English-language studies referenced in MEDLINE or EMBASE (January 1966 to September 1993) were reviewed. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure; and dilated cardiomyopathy in conjunction with the terms anticoagulation, cerebrovascular disorders, stroke, and thromboembolism. STUDY SELECTION: All studies with separate data for patients with chronic heart failure not receiving anticoagulants were included. Articles addressing valvular heart disease or heart failure secondary to acute myocardial infarction or Chagas' disease were excluded. Studies of the occurrence of left ventricular mural thrombi were also reviewed. DATA EXTRACTION AND SYNTHESIS: Inclusion and exclusion criteria, prevalence of atrial fibrillation, mean follow-up, and the occurrence of arterial thromboembolic events were extracted. If the incidence was not given, this was estimated using the proportion of patients with events divided by the mean follow-up. CONCLUSION: The incidence of arterial thromboembolism ranged from 0.9 to 5.5 events per 100 patient-years, with the largest studies reporting incidence of 2.0% and 2.4%. Findings regarding the relationship between ventricular function and thromboembolic events are contradictory. No controlled trial has assessed the efficacy or risks of anticoagulation for patients with heart failure and sinus rhythm, and reported efficacy in case series ranged from 0% to 100%. Until adequate studies are performed, anticoagulation should be discouraged for patients with heart failure who are in sinus rhythm.

Anticoagulants↗
PubMed2004

On rotation, torsion, lateralization, and handedness of the embryonic heart loop: new insights from a simulation model for the heart loop of chick embryos.

The internal organs of vertebrates show specific anatomical left-right asymmetries. The embryonic heart is the first organ to develop such asymmetries during a process called dextro-looping. Thereby the initially straight heart tube curves toward its original ventral side and the resulting bend becomes displaced toward the right side of the embryo. Abnormal displacement of the heart loop toward the left is rare and is called levo-looping. Descriptive studies have shown that the lateralization of the heart loop is driven by rotation around its dorsal mesocardium. However, nothing was known on the modes of this process. To gain insight into this subject, different modes of rotation were tested in a simulation model for the looping chick embryo heart. The morphological phenotypes obtained in this model were compared with normal and mirror-imaged embryonic hearts. The following observations were made. One, rotation of the heart loop around its dorsal mesocardium has two consequences: first, lateral displacement of its bending portion either toward the right (D-loop) or left (L-loop) side of the embryo, and second, torsion of the cardiac bend into a helical structure that is wound either clockwise (right-handed helix) or counterclockwise (left-handed helix). The normal loop presents as a D-loop with left-handed helical winding and its mirror image presents as an L-loop with right-handed helical winding. This conflicts with the use to define D-loops as right- and L-loops as left-handed structures. Two, dextro-looping might be driven almost exclusively by rightward rotation of the arterial pole of the loop. It becomes complemented by leftward rotation of the venous pole during the subsequent phase of looping. An inverse mode of rotation might drive levo-looping. Three, the two different helical configurations of heart loops both can occur as right-sided, median, or left-sided positional variants. When viewed from the front, all right-sided variants appear as D-loops and all left-sided variants appear as L-loops at the end of dextro- or levo-looping. Their true asymmetric phenotypes become fully apparent only after simulation of the subsequent phase of looping. The terms D- and L-loop obviously do not fully define the chirality of heart loops. The chirality of their helical configuration should be defined, too. The implications of these data with respect to molecular and experimental data are discussed.

Animals↗
PubMed1979

Instructed heart rate control in a high heart rate population.

Forty college students were selected from a large number of introductory psychology students on the basis of high heart rate during an initial screening session. Subjects were then contacted and participated in two additional sessions during which heart rate, respiration rate, and skin conductance measures were obtained. Each session consisted of a baseline period followed by five trial periods during which subjects attempted to control their heart rate or performed a visual tracking task. Subjects were randomly assigned to one of four groups. One group served as a control and monitored a visual feedback display driven by their own heart rate but received no instructions to decrease their heart rate. In contrast, the three heart rate control groups were instructed to decrease heart rate during the trial periods by utilizing a relaxation procedure, proportional biofeedback, or proportional biofeedback plus criterion information. No group differences were present during the baseline periods. During feedback trials, however, all the training groups differed from the control in heart rate but did not differ from each other. It is suggested that feedback displays may not facilitate heart rate reduction beyond the level achieved by instructing subjects to use a general relaxation procedure.

Attention↗
PubMed1976

Anoxidative work and metabolism of isolated perfused rat hearts as influenced by artificially increased heart rate.

Under anoxidative conditions the capacity of mechanical activity and the metabolism of isolated rat hearts were studied at various pacemaker-induced heart rates. Isovolumic work decreased to about one third of its initial rate within a 5 min period of anoxidative perfusion and remained almost constant during a further 10 min observation time. Increased heart rate (100, 175, and 250 b.p.m.) was associated with an increase in left ventricular diastolic pressure and with decreases in systolic pressure and maximal dp/dt. Lactate production, tissue creatine phosphate and inorganic phosphate had no consistent relationship to heart rate, whereas tissue ATP decreased with increasing heart rate. It is concluded that the rate of anoxidative isovolumic work cannot be increased by raising the heart rate since anoxidative carbohydrate breakdown cannot be more activated than at the lowest heart rate studied and cannot be more activated than at the lowest heart rate studied and cannot exceed a rate of 30 mumol hexose/min-g dry weight in the perfused heart.

Animals↗
PubMed1988

The epidemiology of resting heart rate in a national sample of men and women: associations with hypertension, coronary heart disease, blood pressure, and other cardiovascular risk factors.

Few reports have been published on the epidemiology of heart rate in general populations including women and blacks. In the first cycle of the National Health Examination Survey, resting heart rate was significantly higher in women than in men at each age in both races. Age and race were inconsistently related to heart rate, black men having slightly lower rates than white men at ages 18 to 34. The product of heart rate and mean blood pressure was consistently highest in black women. Heart rate was associated with obesity, waist girth, and waist-to-hip girth ratio in men under 55 years and with blood pressure and post-load serum glucose in all groups. Sex differences at each age were larger (6 to 14 beats/min) when adjusted for multiple variables. Multivariate linear regression analysis confirmed the independent associations of heart rate with blood pressure and serum glucose. After controlling for other risk factors, prevalent hypertensive subjects had higher heart rates than normotensive individuals in all groups. Further research is needed to elucidate mechanisms of the associations of resting heart rate with sex, risk factors, coronary heart disease, and mortality.

Adolescent↗
PubMed1995

Effects of hypertrophy and heart failure on [Na+]i in pressure-overloaded guinea pig heart.

Intracellular free sodium levels ([Na+]i) were assessed with 23Na nuclear magnetic resonance (NMR) spectroscopy in isolated, Langendorff-perfused normal, compensated hypertrophied, and hypertrophied failing guinea pig hearts under several conditions. Baseline [Na+]i measured with a shift reagent was significantly greater than normal in the compensated hypertrophied hearts (12.8 +/- 1.2 mmol/L v 6.4 +/- 0.7 mmol/L, means +/- SEM, P < .01), but not in the hypertrophied failing hearts (8.7 +/- 1.9 mmol/L, P = N.S.). Moreover, the highest levels of [Na+]i were seen just 3 to 4 weeks after aortic constriction. [Na+]i was inversely related to both time after aortic constriction (R = -0.71, P < .03) and to the degree of left ventricular hypertrophy (R = -0.79, P < .01), suggesting that the hypertrophied failing heart is capable of maintaining relatively normal [Na+]i. In addition, triple quantum filtered NMR measurements were made to assess changes in [Na+]i subsequent to altered perfusion or loading conditions. In hypertrophied failing hearts, but not normal hearts, low coronary perfusion pressure (60 cm H2O) was associated with relatively higher [Na+]i (ANOVA, P < .05), suggesting greater sensitivity of hypertrophied failing hearts to hypoperfusion. On the other hand, when all hearts were perfused at 90 cm H2O and intraventricular balloon volume was increased from 100 microL to 300 microL, [Na+]i increased significantly only in the normal guinea pig hearts (12.3 +/- 1.8%, P < .01). These findings suggest complex changes in the expression or modulation of proteins involved in Na+ regulation. Interpretation regarding the physiological significance of these changes depends on the specific mechanism(s) proposed. Previous work in this and other models of hypertrophy suggest that changes in the number or activity of both Na(+)-K(+)-ATPase and Na(+)-Ca2+ exchange proteins are involved.

Analysis of Variance↗
PubMed2004

Heart rate variability in severe right or left heart failure: the role of pulmonary hypertension and resistances.

BACKGROUND: The decrease in heart rate variability (HRV) might be related to the hemodynamic status in heart failure. However, HRV in patients with severe isolated right heart failure has not been extensively studied. AIMS: This study compared HRV in patients with congestive heart failure (CHF) and in patients with isolated right heart failure. METHODS: Time and frequency domain analysis of HRV on 24-h ECG recording was assessed in 15 healthy subjects and in two groups of patients with severe heart failure awaiting heart or heart/lung transplantation. These were 15 patients with CHF due to idiopathic dilated cardiomyopathy (IDC) and 10 patients with isolated right heart failure due to primary pulmonary hypertension (PPH). RESULTS: Measurement of HRV were significantly decreased in both groups of patients compared with the control group. Patients with IDC had higher pulmonary capillary wedge pressure than patients with PPH (P=0.04) but lower pulmonary artery pressure and lower pulmonary vascular resistance (PVR) (P<0.0001). However, all the measurements of HRV were significantly lower in patients with IDC than in patients with PPH (range 22-77%, P<0.05 to P<0.01). None of the HRV measurements correlated with filling pressure measurements. CONCLUSIONS: The increase in pulmonary vascular resistance in heart failure is not the main causal factor behind a decrease in HRV.

Adult↗
PubMed2004

Implementation of guidelines for management of heart failure in heart failure clinic: effects beyond pharmacological treatment.

BACKGROUND: Patients with heart failure have scarce knowledge of their condition and frequently report poor quality of life. In spite of numerous studies showing improvement of survival and reduction in hospitalizations, several epidemiological studies showed that substantial proportion of patients are not receiving appropriate treatment. Intensive multidisciplinary approach can improve management of the patients with heart failure. AIM: To assess the efficacy of intensive patient management in heart failure clinic with respect to patient knowledge, pharmacological management, and quality of life. METHODS: From outpatients, visiting the heart failure clinic in period form March 2002 to March 2003, we prospectively enrolled patients with heart failure due to systolic dysfunction. Patient knowledge about their condition was assessed by a knowledge questionnaire. Data on their clinical characteristics, diagnostic and pharmacological management were analyzed. Quality of life was assessed with Minnesota Living with Heart Failure Questionnaire (MLHFQ). Patients rated their quality of life and heath on a seven-category descriptive scale from 1 (best) to 7 (worst). Data are shown as mean (S.D.). RESULTS: In this period we treated 50 patients (33 men), aged 67 (12) years. Patient knowledge about their condition improved after two visits to heart failure clinic (4.8 (1.5) vs. 7.3 (1.4), p<0.001). More patients were treated with beta blockers (40% vs. 84%, p<0.001) while there was a positive trend for treatment with angiotensin-converting enzyme inhibitors (94% vs. 98%) and spironolactone (54% vs. 70%). Equivalent mean daily dose of enalapril (11.0 (11.0) mg to 16.7 (8.7) mg, p<0.001) and carvedilol (13.0 (11.5) mg to 32.1 (18.2) mg, p<0.001) increased. Out-patient management was associated with improvement of MLHFQ score (47 (18) vs. 34 (16)), NYHA class (2.9 (0.4) vs. 2.5 (0.7)), quality of life score (5.3 (1.1) vs. 3.7 (1.0)), and health score (5.1 (1.1) vs. 3.7 (1.1)) (p<0.001 for all). CONCLUSIONS: Intensive management in heart failure clinic can be effective for translation of guidelines into clinical practice. It also improves patient's knowledge and quality of life as well as reduces the hospitalizations in heart failure patients.

Aged↗