Alterations in ventricular excitability in conscious dogs during development of chronic heart failure

1986 ◽  
Vol 250 (6) ◽  
pp. H1022-H1029 ◽  
Author(s):  
C. W. White ◽  
M. J. Mirro ◽  
D. D. Lund ◽  
D. J. Skorton ◽  
N. G. Pandian ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Time Course ◽  
Left Ventricular ◽  
Conscious Dogs ◽  
Maximum Increase ◽  
Electrophysiological Properties ◽  
Cycle Lengths ◽  
The Right

Arrhythmias in patients with heart failure may result from altered electrophysiological properties of the myocardium. To examine changes in ventricular excitability during cardiac failure and to relate these changes to ventricular structural and neurochemical abnormalities, right ventricular failure was produced in dogs by pulmonary artery banding and by creating tricuspid regurgitation. Right and left ventricular excitability thresholds were tested biweekly in heart failure (HF) and sham-operated conscious dogs by means of strength-duration curves (1-40 ms) at basic cycle lengths (BCL) of 300-500 ms until time of death (21-188 days). Marked increases in the excitability threshold of the right ventricle occurred in HF (mean maximum % increase, 205 +/- 42 at BCL 500 ms). Smaller, though significant increases in the left ventricular excitability threshold in HF were also seen (mean maximum % increase 103 +/- 36 at BCL 500 ms). Increases in the excitability threshold of the left as well as the right ventricles occurred, even though ventricular dilation (2-D Echo) was confined to the right ventricle. The time course of changes in the excitability threshold was variable (maximum occurrence at 21 +/- 3 days right ventricle, 23 +/- 11 days left ventricle). Tyrosine hydroxylase activity and norepinephrine content of the right ventricle were markedly depleted at death, when the excitability threshold was high. Similar though nonsignificant trends in reductions of these sympathetic neurochemicals were seen in the left ventricle. Levels of choline acetyltransferase and QNB binding in both ventricles were unaffected.

Regulation of K+ and Ca2+ channels in experimental cardiac failure

1991 ◽  
Vol 261 (6) ◽  
pp. H1979-H1987 ◽  
Author(s):  
M. Gopalakrishnan ◽  
D. J. Triggle ◽  
A. Rutledge ◽  
Y. W. Kwon ◽  
J. A. Bauer ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Cardiac Failure ◽  
Radioligand Binding ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
The Right

To examine the status of ATP-sensitive K+ (K+ATP) channels and 1,4-dihydropyridine-sensitive Ca2+ (Ca2+DHP) channels during experimental cardiac failure, we have measured the radioligand binding properties of [3H]glyburide and [3H]PN 200 110, respectively, in tissue homogenates from the rat cardiac left ventricle, right ventricle, and brain 4 wk after myocardial infarction induced by left coronary artery ligation. The maximal values (Bmax) for [3H]glyburide and [3H]PN 200 110 binding were reduced by 39 and 40%, respectively, in the left ventricle, and these reductions showed a good correlation with the right ventricle-to-body weight ratio in heart-failure rats. The ligand binding affinities were not altered. In the hypertrophied right ventricle, Bmax values for both the ligands were not significantly different when data were normalized to DNA content or right ventricle weights but showed an apparent reduction when normalized to unit protein or tissue weight. Moderate reductions in channel densities were observed also in whole brain homogenates from heart failure rats. Assessment of muscarinic receptors, beta-adrenoceptors and alpha 1-adrenoceptors by [3H]quinuclidinyl benzilate, [3H]dihydroalprenolol, and [3H]prazosin showed reductions in left ventricular muscarinic and beta-adrenoceptor densities but not in alpha 1-adrenoceptor densities, consistent with earlier observations. It is suggested that these changes may in part contribute to the pathology of cardiac failure.

scholarly journals Different reverse remodelling between left ventricle and right ventricle in fulminant heart failure due to giant cell myocarditis: a case report

2021 ◽  
Vol 5 (8) ◽  
Author(s):  
Hiroaki Yokoyama ◽  
Masashi Yamaguchi ◽  
Kazuki Tobita ◽  
Shigeru Saito
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Giant Cell ◽  
Functional Recovery ◽  
Left Ventricular ◽  
Giant Cell Myocarditis ◽  
Reverse Remodelling ◽  
The Right ◽  
Immunosuppression Therapy

Abstract Background Giant cell myocarditis (GCM) is a rare cause of fulminant heart failure (HF). The most common presentation is progressive hemodynamic deterioration, and a few cases present with idiopathic complete atrioventricular block (cAVB). The prognosis of GCM is poor, and GCM patients usually die of HF and ventricular arrhythmia unless cardiac transplantation is performed. Few reports have described the effects of treatments such as immunosuppression and detailed reverse remodelling in GCM patients. Case summary A 69-year-old female presented with cAVB. Transvenous pacemaker was implanted via the left subclavian vein. One and a half months later, she exhibited left ventricular dyssynchrony and lower left ventricular ejection fraction (LVEF), resulting in hospitalization for HF. She received cardiac resynchronization therapy; however, this had no apparently positive effects on her cardiac function. To investigate the cause of the lower LVEF, an endomyocardial biopsy was taken from the right ventricular septum. She was diagnosed with GCM and immediately received immunosuppression therapy with prednisolone and ciclosporin. This resulted in the functional recovery of the right ventricle; on the other hand, the left ventricle had still not recovered based on transthoracic echocardiography. Fortunately, she successfully recovered from severe HF without recurrence. Discussion This is a case of fulminant HF due to GCM which initially presented as cAVB. Moreover, this case demonstrates the quite difference of the functional recovery between the left ventricle and the right ventricle with immunosuppression therapy.

scholarly journals Left ventricular noncompaction—a rare cause of triad: heart failure, ventricular arrhythmias, and systemic embolic events: a case report 

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Despina Toader ◽  
Alina Paraschiv ◽  
Petrișor Tudorașcu ◽  
Diana Tudorașcu ◽  
Constantin Bataiosu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricle ◽  
Ventricular Arrhythmias ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Left Ventricular Noncompaction ◽  
Ventricular Noncompaction ◽  
The Right

Abstract Background Left ventricular noncompaction is a rare cardiomyopathy characterized by a thin, compacted epicardial layer and a noncompacted endocardial layer, with trabeculations and recesses that communicate with the left ventricular cavity. In the advanced stage of the disease, the classical triad of heart failure, ventricular arrhythmia, and systemic embolization is common. Segments involved are the apex and mid inferior and lateral walls. The right ventricular apex may be affected as well. Case presentation A 29-year-old Caucasian male was hospitalized with dyspnea and fatigue at minimal exertion during the last months before admission. He also described a history of edema of the legs and abdominal pain in the last weeks. Physical examination revealed dyspnea, pulmonary rales, cardiomegaly, hepatomegaly, and splenomegaly. Electrocardiography showed sinus rhythm with nonspecific repolarization changes. Twenty-four-hour Holter monitoring identified ventricular tachycardia episodes with right bundle branch block morphology. Transthoracic echocardiography at admission revealed dilated left ventricle with trabeculations located predominantly at the apex but also in the apical and mid portion of lateral and inferior wall; end-systolic ratio of noncompacted to compacted layers > 2; moderate mitral regurgitation; and reduced left ventricular ejection fraction. Between apical trabeculations, multiple thrombi were found. The right ventricle had normal morphology and function. Speckle-tracking echocardiography also revealed systolic left ventricle dysfunction and solid body rotation. Abdominal echocardiography showed hepatomegaly and splenomegaly. Abdominal computed tomography was suggestive for hepatic and renal infarctions. Laboratory tests revealed high levels of N-terminal pro-brain natriuretic peptide and liver enzymes. Cardiac magnetic resonance evaluation at 1 month after discharge confirmed the diagnosis. The patient received anticoagulants, antiarrhythmics, and heart failure treatment. After 2 months, before device implantation, he presented clinical improvement, and echocardiographic evaluation did not detect thrombi in the left ventricle. Coronary angiography was within normal range. A cardioverter defibrillator was implanted for prevention of sudden cardiac death. Conclusions Left ventricular noncompaction is rare cardiomyopathy, but it should always be considered as a possible diagnosis in a patient hospitalized with heart failure, ventricular arrhythmias, and systemic embolic events. Echocardiography and cardiac magnetic resonance are essential imaging tools for diagnosis and follow-up.

Ventricular systolic interdependence: volume elastance model in isolated canine hearts

1987 ◽  
Vol 253 (6) ◽  
pp. H1381-H1390 ◽  
Author(s):  
W. L. Maughan ◽  
K. Sunagawa ◽  
K. Sagawa
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cross Talk ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Systolic Volume ◽  
The Right

To analyze the interaction between the right and left ventricle, we developed a model that consists of three functional elastic compartments (left ventricular free wall, septal, and right ventricular free wall compartments). Using 10 isolated blood-perfused canine hearts, we determined the end-systolic volume elastance of each of these three compartments. The functional septum was by far stiffer for either direction [47.2 +/- 7.2 (SE) mmHg/ml when pushed from left ventricle and 44.6 +/- 6.8 when pushed from right ventricle] than ventricular free walls [6.8 +/- 0.9 mmHg/ml for left ventricle and 2.9 +/- 0.2 for right ventricle]. The model prediction that right-to-left ventricular interaction (GRL) would be about twice as large as left-to-right interaction (GLR) was tested by direct measurement of changes in isovolumic peak pressure in one ventricle while the systolic pressure of the contralateral ventricle was varied. GRL thus measured was about twice GLR (0.146 +/- 0.003 vs. 0.08 +/- 0.001). In a separate protocol the end-systolic pressure-volume relationship (ESPVR) of each ventricle was measured while the contralateral ventricle was alternatively empty and while systolic pressure was maintained at a fixed value. The cross-talk gain was derived by dividing the amount of upward shift of the ESPVR by the systolic pressure difference in the other ventricle. Again GRL measured about twice GLR (0.126 +/- 0.002 vs. 0.065 +/- 0.008). There was no statistical difference between the gains determined by each of the three methods (predicted from the compartment elastances, measured directly, or calculated from shifts in the ESPVR). We conclude that systolic cross-talk gain was twice as large from right to left as from left to right and that the three-compartment volume elastance model is a powerful concept in interpreting ventricular cross talk.

scholarly journals Genomic modulation of mitochondrial respiratory genes in the hypertrophied heart reflects adaptive changes in mitochondrial and contractile function

2007 ◽  
Vol 293 (5) ◽  
pp. H2819-H2825 ◽  
Author(s):  
Makhosazane Zungu ◽  
Maria Pilar Alcolea ◽  
Francisco José García-Palmer ◽  
Martin E. Young ◽  
M. Faadiel Essop
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Respiratory Function ◽  
Hypobaric Hypoxia ◽  
Contractile Function ◽  
Left Ventricular ◽  
Transcript Levels ◽  
Mitochondrial Number ◽  
The Right ◽  
Mitochondrial Respiratory

We hypothesized the coordinate induction of mitochondrial regulatory genes in the hypertrophied right ventricle to sustain mitochondrial respiratory capacity and contractile function in response to increased load. Wistar rats were exposed to hypobaric hypoxia (11% O2) or normoxia for 2 wk. Cardiac contractile and mitochondrial respiratory function were separately assessed for the right and left ventricles. Transcript levels of several mitochondrial regulators were measured. A robust hypertrophic response was observed in the right (but not left) ventricle in response to hypobaric hypoxia. Mitochondrial O2 consumption was increased in the right ventricle, while proton leak was reduced vs. normoxic controls. Citrate synthase activity and mitochondrial DNA content were significantly increased in the hypertrophied right ventricle, suggesting higher mitochondrial number. Transcript levels of nuclear respiratory factor-1, peroxisome proliferator-activated receptor-γ-coactivator-1α, cytochrome oxidase (COX) subunit II, and uncoupling protein-2 (UCP2) were coordinately induced in the hypertrophied right ventricle following hypoxia. UCP3 transcript levels were significantly reduced in the hypertrophied right ventricle vs. normoxic controls. Exposure to chronic hypobaric hypoxia had no significant effects on left ventricular mitochondrial respiration or contractile function. However, COXIV and UCP2 gene expression were increased in the left ventricle in response to chronic hypobaric hypoxia. In summary, we found coordinate induction of several genes regulating mitochondrial function and higher mitochondrial number in a model of physiological right ventricular hypertrophy, linking the efficiency of mitochondrial oxidative phosphorylation and respiratory function to sustained contractile function in response to the increased load.

Delayed enhancement imaging in a contemporary patient cohort following correction of tetralogy of Fallot

2014 ◽  
Vol 25 (7) ◽  
pp. 1268-1275 ◽  
Author(s):  
Uta Preim ◽  
Philipp Sommer ◽  
Janine Hoffmann ◽  
Jana Kehrmann ◽  
Lukas Lehmkuhl ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Tetralogy Of Fallot ◽  
Nyha Class ◽  
Left Ventricular ◽  
Delayed Enhancement ◽  
Volume Index ◽  
Delayed Enhancement Imaging ◽  
The Right ◽  
Myocardial Scars

AbstractObjectiveTo test the hypothesis that myocardial scars after repair of tetralogy of Fallot are related to impaired cardiac function and adverse clinical outcome.MethodsA total of 53 patients were retrospectively analysed after repair of tetralogy of Fallot. The median patient age was 20 years (range 2–48).Cardiac MRI with a 1.5 T magnet included cine sequences to obtain volumes and function, phase-sensitive inversion recovery delayed enhancement imaging to detect myocardial scars, and flow measurements to determine pulmonary regurgitation fraction. In addition, clinical parameters were obtained.ResultsAn overall 83% of patients were in NYHA class I. All patients with the exception of 2 (96%) had pulmonary insufficiency. Mean ejection fraction and end-diastolic volume index were 46% and 128 ml/m2 for the right ventricle and 54% and 82 ml/m2 for the left ventricle, respectively. Excluding enhancement of the septal insertion and prosthetic patches, delayed enhancement was seen in 11/53 cases (21%). Delayed enhancement of the right ventricle was detected in 6/53 patients (11%) and of the left ventricle in 5/53 patients (9%). The patient group with delayed enhancement was significantly older (p=0.003), had later repair (p=0.007), and higher left ventricular myocardial mass index (p=0.009) compared with the group without delayed enhancement.ConclusionsThis study reveals that scarring is common in patients after surgical repair of tetralogy of Fallot and is associated with older age and late repair. However, there was no difference in right ventricular function, NYHA class, or occurrence of clinically relevant arrhythmias between patients with and those without myocardial scars.

scholarly journals Epigenetics, inflammation and metabolism in right heart failure associated with pulmonary hypertension

2017 ◽  
Vol 7 (3) ◽  
pp. 572-587 ◽  
Author(s):  
Nolwenn Samson ◽  
Roxane Paulin
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Pressure Overload ◽  
Right Heart Failure ◽  
Left Ventricular ◽  
Ventricular Failure ◽  
Pulmonary Arterial ◽  
Ventricle Hypertrophy ◽  
The Right

Right ventricular failure (RVF) is the most important prognostic factor for both morbidity and mortality in pulmonary arterial hypertension (PAH), but also occurs in numerous other common diseases and conditions, including left ventricle dysfunction. RVF remains understudied compared with left ventricular failure (LVF). However, right and left ventricles have many differences at the morphological level or the embryologic origin, and respond differently to pressure overload. Therefore, knowledge from the left ventricle cannot be extrapolated to the right ventricle. Few studies have focused on the right ventricle and have permitted to increase our knowledge on the right ventricular-specific mechanisms driving decompensation. Here we review basic principles such as mechanisms accounting for right ventricle hypertrophy, dysfunction, and transition toward failure, with a focus on epigenetics, inflammatory, and metabolic processes.

scholarly journals Electrophysiological remodeling of the right ventricle in experimental heart failure of different etiologies

2019 ◽  
Vol 18 (2) ◽  
pp. 165-174
Author(s):  
A. S. Tsvetkova ◽  
V. V. Krandycheva ◽  
S. N. Kharin
Keyword(s):  
Heart Failure ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Ventricular Repolarization ◽  
Channel System ◽  
Electrophysiological Properties ◽  
Experimental Heart Failure ◽  
Epicardial Layer ◽  
Measured Activation ◽  
The Right

The aim of the study was to evaluate electrophysiological remodeling of the right ventricle in rats in experimental heart failure of different etiologies. Materials and methods. Isadrin-, doxorubicin- and monocrotaline-induced heart failure models were developed. Unipolar epicardial electrograms of the ventricles (256 recording sites) were recorded using a 144-channel system. The cardiac output and pressure in both ventricles of the heart were measured. Activation-recovery intervals were used as an index of duration of local repolarization, and the general and local dispersions of activation-recovery intervals were used as an index of heterogeneity of ventricular repolarization. Results. In all models of heart failure, the following were identified: 1) non-uniform prolongation of repolarization with the greatest elongation at the apex of the right ventricle; 2) an increase in apicobasal differences of repolarization with the greatest change in the right ventricle; 3) an increase in the heterogeneity of the repolarization of the epicardial layer of the ventricles with heterogeneous changes in the local heterogeneity of repolarization and a decrease in the interregional differences in the heterogeneity of the electrophysiological properties of the myocardium; 4) more pronounced changes in the repolarization of the right ventricle than in the repolarization of the left ventricle. Conclusion. Thus, irrespective of the cause of the heart failure, the following changes occur: 1) prolongation of the right ventricular repolarization occurs non-uniformly (mostly due to the apical area), which results in an increase in the right ventricular repolarization heterogeneity; 2) an increase in the heterogeneity of right ventricular repolarization is observed, which causes an increase in the overall heterogeneity of the ventricular epicardial surface.

Growth of the Heart and Lungs in Hypoxic Rodents: A Model of Human Hypoxic Disease

1974 ◽  
Vol 46 (3) ◽  
pp. 375-391 ◽  
Author(s):  
Carolin Hunter ◽  
Gwenda R. Barer ◽  
J. W. Shaw ◽  
E. J. Clegg
Keyword(s):  
Body Weight ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Left Ventricular ◽  
Muscle Fibre Size ◽  
Littermate Control ◽  
Normal Environment ◽  
The Right ◽  
Rats And Mice ◽  
The Relationship

1. Rats and mice were kept in a decompression chamber at 52 kPa (390 mmHg) for 1–4 weeks and their hearts and lungs were compared with littermate control animals. In both species growth was retarded in the hypoxic environment. 2. In both species small peripheral lung vessels became thickened, developing two elastic laminae with a muscular coat between. A method was developed for assessing these changes in large numbers of animals. The number of thick-walled vessels was still high after 4 weeks' recovery in a normal environment. Pulmonary vascular resistance, measured by a perfusion method, increased in animals kept in the decompression chamber. 3. Mouse lungs became heavier than controls; the increase was not due to a greater fluid content. Rat lungs were heavy in relation to body weight but not heavier than controls; there may have been slight thickening of alveolar walls. Chest areas, measured from radiographs, were large relative to body weight in hypoxic rats. 4. The relationship between right and left ventricular weight and body weight was studied in normal rats and mice. The left ventricle grew about four times more quickly than the right. Changes in ventricular weights during exposure in the decompression chamber and subsequent recovery in a normal environment were related to these normal growth curves. 5. In both species the right ventricle grew abnormally fast in the decompression chamber. It was absolutely heavier than that of controls and relative to body weight was extremely heavy. After 4 weeks' recovery the relationship between right ventricular weight and body weight was nearly normal; this was achieved by retarded growth or actual loss of weight. 6. In mice the left ventricle grew normally in the decompression chamber and was heavy in relation to body weight. In rats its growth was retarded in the chamber and was normal in relation to body weight. 7. Morphometry of the hypertrophied right ventricle showed that muscle fibre size and total muscle mass had increased in hypoxic rats. There had been no increase in nuclear mass, but the perinuclear sarcoplasm had increased. All layers of the myocardium participated in the hypertrophy.

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