Left heart failure and right heart failure because of pulmonary disease

Transcription

1 Left heart failure and right heart failure because of pulmonary disease Dr. Szathmári Miklós Semmelweis University First Department of Medicine 28. Oct

2 Heart failure (HF)- definition HF is a clinical syndrome that occurs in patients who - because of an inherited or acquired abnormality of heart structure and/or function - develop a constellation of clinical symptoms (dyspnoea and fatigue) and signs (oedema and rales) that lead a poor quality of life, and a shortened life expectancy. Diagnostic criteria's: Clinical symptoms of HF at rest or by exertion Identification of abnormal heart function in rest by objective imaging tools Improvement of the symptoms of HF by adequate therapy HF patients are categorized into one of two groups: HF with a depressed ejection fraction (<40%)- systolic failure HF with a preserved ejection fraction ( 40%) diastolic failure

3 Control of cardiac performance and output The stroke volume of the ventricle in the intact heart depend on three major influences: The length of the muscle at the onset of contraction (the preload, surrogate parameter is the enddiastolic volume of the ventricle,edv). Within limits the stroke volume relates closely the enddiastolic volume. The tension that the muscle is called upon to develop during contraction (afterload), the load that opposes shortening, or the tension developed in the ventricular wall during ejection. The contractility of the muscle (the extent and velocity of shortening at any given preload and afterload).

4 Determinants of stroke volume Ventricular preload Blood volume Distribution of blood volume (body position, intrathoracic pressure, venous tone, etc.) Atrial contraction Ventricular afterload Systemic vascular resistance Arterial blood pressure Elasticity of arterial tree Ventricular wall tension Radius, wall thickness Myocardial contractility Intramyocardial Ca+ Cardiac adrenergic nerve activity Circulating catecholamine Cardiac rate Myocardial ischemia Myocardial cell death Myocardial fibrosis Alteration of sarcomeric and cytoskeletal proteins Ventricular remodelling Chronic overexpression of neurohormones Chronic myocardial hypertrophy

5 Functional classification of heart failure (NYHA) NYHA functional classification: Class I. Without limitation of physical activity. No symptoms with ordinary exertion (latent decompensation) Class II. Slight limitation of physical activity. Ordinary activity causes symptoms, fatigue, palpitation, dyspnoea, anginal pain. (subdecompensation) Class III. Marked limitation of physical activity. Less than ordinary activity causes symptoms. Class IV. Inability to carry out any physical activity without discomfort. Symptoms are present at rest.

6 Epidemiology of heart failure The overall prevalence of HF in the adult population in developed countries is 2%.Over the age 65 affects 6-10% of people. The overall prevalence of HF is thought to be increasing (most common cause of hospital admissions), in part because current therapies of cardiac disorders, such as myocardial infarction, valvular heart disease, and arrhythmias, are allowing the patients to survive longer. Heart failure is the most common cause of death (In the USA death/year) Patients with symptoms at rest have a 30-70% annual mortality rate. Patients with symptoms with moderate activity have an annual mortality rate of 5-10%

7 Pathogenesis of heart failure with depressed ejection fraction HF begins after an index event (acute MI, or gradual onset as in the case of pressure or volume overload) produces an initial decline in pumping activity (systolic dysfunction). The compensatory mechanisms are activated, including: The adrenergic nervous system to increase the myocardial contractility The renin-angiotensin-aldosterone system for maintaining cardiac output through increased retention of salt and water The activation a molecules (BNP, NO, PGE2, PGI2) and cytokin system that offset the peripheral vasoconstriction In the short term these systems are able to restore cardiovascular function with the result that the patient remain asymptomatic. However, with time the sustained activation of these systems can lead to secondary end-organ damage within the ventricle, with left ventricular remodelling and subsequent cardiac decompensation.

8 Pathogenesis of heart failure Index event, that decreases cardiac output Increased sympathetic activity Stimulation of cardioregulatory centre Stimulation of RAAS Increased AVP secretion Activation of vasodilatators (BNP,NO, PGs, TNF-α Influence on heart rate, preload, contractility and afterload The functional capacity is preserved or is depressed only minimally Genetic background, age, gender, environment Symptomatic heart failure by activation of left ventricle remodelling (mass, shape, volume, composition

9 Pathogenesis of heart failure with preserved ejection fraction Diastolic dysfunction Impaired myocardial relaxation, an ATP-dependent process that is regulated by uptake of cytoplasmatic Ca2+ into the sarcoplasmatic reticulum Reduction in ATP concentration in case of ischemia Decreased left ventricle compliance (from hypertrophy or fibrosis) An increase in heart rate disproportionately shortens the time of diastolic filling, which may lead to elevated left ventricle filling pressures. Elevated LV end-diastolic filling pressures results in increases in pulmonary capillary pressures, which can contribute to the dyspnoea Increased vascular and ventricular stiffness may be also important

10 Left ventricular remodelling The transition to symptomatic HF is accompanied by increasing activation of neurohormonal, adrenergic, and cytokine systems that lead to series of adaptive changes within the myocardium, collectively referred to as left ventricle remodelling. These changes include : Myocyte hypertrophy Alteration in the contractile properties of myocyte Progressive loss of myocyte through necrosis, apoptosis β-adrenergic desensitization Abnormal myocardial energetic and metabolism Reorganization of extracellular matrix with dissolution of organized structural collagen weave, replacement with an interstitial collagen matrix that does not provide structural support to the myocytes

11 Left ventricle remodelling on macrostructural level Change of LV geometry from ellipsoid to spherical shape an increase of meridional wall stress Increase in end-diastolic volume LV wall thinning. Together with the increased afterload leads to decreased stroke volume High end-diastolic wall stress leads to Hypoperfusion of the subendocardium worsening of LV function Increased oxidative stress Sustained expression of wall-stretch-activated genes (AII, TNF) Because of increased sphericity the papillary muscles are pulled apart, resulting in incompetence of the mitral valve mitral regurgitation further hemodynamic overloading of the ventricle

12 Mechanical burdens that are engendered by left ventricle remodelling can be expected to lead to decreased forward cardiac output increased left ventricle dilatation (stretch) increased hemodynamic overloading

13 Different forms of left ventricle overload Pressure (systolic) overload Increased afterload Aortic stenosis, hypertension Myocardial hypertrophy with minimal dilatation Volume (diastolic) overload Increased preload Mitral or aortic regurgitation Left ventricle dilatation

14 Clinical symptoms and physical signs of the heart failure Fatigue Dyspnoea Tachycardia Cyanosis Pulmonary congestion Phlebohypertension Hepatomegaly Congestion of the kidney Other symptoms

15 Clinical symptoms of the heart failure Fatigue The consequence of low cardiac output, but other noncardiac co-morbidities (anaemia, musculoskeletal abnormalities) also contribute to this symptom Dyspnoea (the most important mechanism is the pulmonary congestion with accumulation of interstitial or intraalveolar fluid. Other factors are reduction in pulmonary compliance, increased airway resistance, respiratory muscle weakness, and impaired sensitivity of respiratory centre) Clinical manifestations: Effort dyspnoea Dyspnoea at rest Orthopnoea: Dyspnoea occurring in the recumbent position. Acute episodic shortness of breath Cheyne-Stokes respiration

16 Acute and/or periodic forms of dyspnoea Paroxysmal nocturnal dyspnoea Acute episodes of severe shortness of breath and coughing that occur at night and awaken the patient from sleep, usually 1-3 after the patient retires. It manifests by coughing or wheezing, possible because of increased pressure in the bronchial artery leading to airway compression, along with interstitial pulmonary oedema. It does not improve in upright position It can be associated with hypertension, aortic vitium, dilated cardiomyopathy. Cheyne-Stokes respiration Caused by diminished sensitivity of respiratory centre to arterial PCO 2. In the apnoeic phase the patient can be unconscious,

17 Cyanosis Bluish colour of the skin and mucous membranes resulting from an increased quantity of reduced haemoglobin( exceeds 40 g/l) in the small blood vessels of those areas. It is usually most marked in the lips, nail beds, ears, and malar eminences Central cyanosis can be detected reliably when arterial O 2 saturation has fallen to 85% (in darkskinned persons 75%)

18 Clinical signs and symptoms of pulmonary congestion Decreased vital capacity of the lung because of interstitial pulmonary oedema Central cyanosis (inhibited gas exchange) Dyspnoea Coughing Brownish sputum (epithel cells containing hemosiderin pigments), eventually haemoptysis Ronchi, wheezing, crackles Accentuated pulmonary component of second heart sound Dilated pulmonary veins on the X-ray

19 Clinical signs and symptoms of rightsided heart failure Gärtner s sign: The veins of the hand remain dilated by the elevation of the arm to the level of the left atrium Distension of the external jugular vein :elevated jugular venous pressure. Positive abdomino-jugular reflux: With sustained pressure on the abdomen the jugular venous pressure becomes abnormally elevated. Hepatomegaly. The enlarged liver is frequently tender. Jaundice and ascites are late finding in heart failure, results from impairment of hepatic function secondary to hepatic congestion and hepatic hypoxia. Proteinuria Anorexia, nausea, and early satiety associated with abdominal pain and fullness relates to oedema of bowel wall and/or to the congested liver.

20 Oedema Oedema: : accumulation of fluid in the interstitial space. Residual imprint of fingers following application of pressure. Latent oedema: (less than 5-6 l fluid retention). Identification: measurement of body weight in the morning and in the evening and/or compare the amount of the urine during the day and during the night. Manifest oedema: usually symmetric, and occurs predominantly in the ankles and pretibial region in ambulatory patients. In bedridden patients, oedema may be found in the sacral area, and the scrotum. Differential diagnosis: varicosity, pes planus, deep vein thrombosis, and v. cava inferior thrombosis)

21 Cor pulmonale Definition: dilatation and hypertrophy of the right ventricle in response to diseases of the pulmonary vasculature and/or lung parenchyma (pulmonary heart disease) Chronic obstructive lung disease and chronic bronchitis are responsible for approximately 50% of the cases of cor pulmonale in developed countries

22 Aetiology of chronic cor pulmonale Diseases leading to hypoxic vasoconstriction Chronic bronchitis COPD Cystic fibrosis Chronic hypoventilation Obesity Neuromuscular diseases Chest wall deformities Living at high altitudes Diseases causing occlusion of the pulmonary vascular bed Recurrent pulmonary thromboembolism Primary pulmonary hypertension Venoocclusive disease Collagen vascular disease Drug-induced lung disease Parenchymal pulmonary diseases Chronic bronchitis COPD Bronchiectasis Idiopathic pulmonary fibrosis Sarcoidosis Pneumoconiosis

23 Pathophysiology of cor pulmonale Pulmonary disease Pulmonary hypertension Alteration in RV volume overload -Exercise -Heart rate -Polycythaemia -Salt and water retention (low CO) Right ventricle dilatation and hypertrophy Right ventricle failure Secondary to alteration of gas exchange - Hypoxia - Hypercapnia - Acidosis

24 Symptoms and signs of cor pulmonale Dyspnoea - result of the increased work of breathing or altered respiratory mechanics Effort-related syncope because of the inability of the RV to deliver blood adequately to left side of the heart Abdominal pain and ascites Lower extremity oedema secondary to neurohormonal activation, elevated RV filling pressure, or increased levels of carbon dioxide and hypoxia, which can lead to peripheral vasodilatation RV heave palpable along the left sternal border or in the epigastrium A systolic pulmonary ejection click to the left of the upper sternum Holosystolic murmur of tricuspidal regurgitation (the intensity of the murmur increases with inspiration) Cyanosis late finding in cor pulmonale