Cor pulmonale
Encyclopedia
Cor pulmonale or pulmonary heart disease is enlargement of the right ventricle of the heart as a response to increased resistance or high blood pressure in the lungs (pulmonary hypertension
).
Chronic
cor pulmonale usually results in right ventricular hypertrophy
(RVH), whereas acute cor pulmonale usually results in dilatation
.
Hypertrophy is an adaptive response to a long-term increase in pressure. Individual muscle cells grow larger(in thickness) and change to drive the increased contractile force required to move the blood against greater resistance.
Dilatation is a stretching (in length) of the ventricle in response to acute increased pressure.
To be classified as cor pulmonale, the cause must originate in the pulmonary circulation
system. Two major causes are vascular changes as a result of tissue damage (e.g. disease, hypoxic injury
, chemical agents, etc.), and chronic hypoxic pulmonary vasoconstriction
. RVH due to a systemic
defect is not classified as cor pulmonale.
When untreated, cor pulmonale can lead to right-heart failure and death.
The heart has two pumping chambers. The left ventricle
pumps blood throughout the body. The right ventricle
pumps blood
to the lungs where it is oxygenated and returned to the left heart for distribution. In normal circumstances, the right heart pumps blood into the lungs without any resistance. The lungs usually have minimal pressure and the right heart easily pumps blood through.
However when there is lung disease present, like emphysema
, chronic obstructive lung disease (COPD) or pulmonary hypertension
- the small blood vessels become very stiff and rigid. The right ventricle is no longer able to push blood into the lungs and eventually fails. This is known as pulmonary heart disease. Pulmonary heart disease is also known as right heart failure or cor pulmonale. The chief cause of right heart failure is the increase in blood pressure in the lungs (pulmonary artery).
. During a cardiac catheterization, a small flexible tube is inserted from the groin and under x ray guidance images of the heart are obtained. Moreover the technique allows measurement of pressures in the lung and heart which provide a clue to the diagnosis.
) are prone to pulmonary artery disease. In infants the earlier the heart disease is treated, the better the prognosis. While pulmonary heart disease is serious, it is much less common than coronary artery disease.
. Chronic congestion in the centrilobular
region of the liver leads to hypoxia and fatty changes of more peripheral hepatocytes, leading to what is known as nutmeg liver
.
, thrombolysis
(enzymatic dissolution of the blood clot) is advocated by some authorities if there is dysfunction of the right ventricle, and is otherwise treated with anticoagulant
s. In COPD, long-term oxygen therapy
may improve cor pulmonale.
Cor pulmonale may lead to congestive heart failure
(CHF), with worsening of respiration due to pulmonary edema
, swelling of the legs due to peripheral edema
and painful congestive hepatomegaly (enlargement of the liver due to tissue damage as explained in the Complications section. This situation requires diuretic
s (to decrease strain on the heart), sometimes nitrate
s (to improve blood flow), phosphodiesterase inhibitor
s such as sildenafil
or tadalafil
and occasionally inotrope
s (to improve heart contractility). CHF is a negative prognostic indicator
in cor pulmonale.
Oxygen
is often required to resolve the shortness of breath. Plus, oxygen to the lungs also helps relax the blood vessels and eases right heart failure. Oxygen is given at the rate of 2 litres per minute. Excess oxygen can be harmful to patients because hypoxia is the main stimulus to respiration. If such hypoxia is suddenly corrected by overflow of oxygen, such stimulus to the respiratory center is suddenly withdrawn and respiratory arrest occurs. When wheezing is present, majority of the patients require bronchodilators. A variety of drugs have been developed to relax the blood vessels in the lung. Calcium channel blockers are used but only work in a few cases. Other novel medications that need to be inhaled or given intravenously include prostacyclin
derivatives.
Cases of COPD with chronic corpulmonale present with secondary polycythemia , if severe it may increase the blood viscosity and contribute to pulmonary hypertension. If hematocrit(PCV) is above 60%, then it is better to reduce the red blood cell count by phlebotomies.
Mucolytic agents like bromhexine and carbocisteine help bring out excessive bronchial secretions more easily by coughing.
All patients with pulmonary heart disease are maintained on blood thinning medications
to prevent formation of blood clots.
When medical therapy fails, one may require a transplant. However, since the lungs are damaged, both the heart and lungs needs to be transplanted. With a shortage of donors this therapy is only done 10-15 times a year in North America.
or chronic obstructive lung disease always end up with right heart failure. When working in environments where there are chemicals, wear masks to prevent inhalation of dust particles.
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
).
Chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
cor pulmonale usually results in right ventricular hypertrophy
Right ventricular hypertrophy
Right ventricular hypertrophy is a form of ventricular hypertrophy affecting the right ventricle.Blood travels through the right ventricle to the lungs via the pulmonary arteries. If conditions occur which decrease pulmonary circulation, meaning blood does not flow well from the heart to the...
(RVH), whereas acute cor pulmonale usually results in dilatation
Vasodilation
Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
.
Hypertrophy is an adaptive response to a long-term increase in pressure. Individual muscle cells grow larger(in thickness) and change to drive the increased contractile force required to move the blood against greater resistance.
Dilatation is a stretching (in length) of the ventricle in response to acute increased pressure.
To be classified as cor pulmonale, the cause must originate in the pulmonary circulation
Pulmonary circulation
Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen-depleted Blood away from the heart, to the Lungs, and returns oxygenated blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn...
system. Two major causes are vascular changes as a result of tissue damage (e.g. disease, hypoxic injury
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
, chemical agents, etc.), and chronic hypoxic pulmonary vasoconstriction
Hypoxic Pulmonary Vasoconstriction
Hypoxic pulmonary vasoconstriction is a paradoxical, physiological phenomenon in which pulmonary arteries constrict in the presence of hypoxia without hypercapnia , redirecting blood flow to alveoli with a higher oxygen content.The process might at first seem illogical, as low oxygen levels should...
. RVH due to a systemic
Systemic
Systemic refers to something that is spread throughout, system-wide, affecting a group or system such as a body, economy, market or society as a whole. Systemic may also refer to:-In medicine:...
defect is not classified as cor pulmonale.
When untreated, cor pulmonale can lead to right-heart failure and death.
Overview
The heart and lung are intricately related. Whenever the heart is affected by disease, the lungs will follow and vice versa. Pulmonary heart disease is by definition a condition when the lungs cause the heart to fail.The heart has two pumping chambers. The left ventricle
Left ventricle
The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...
pumps blood throughout the body. The right ventricle
Right ventricle
The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....
pumps blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
to the lungs where it is oxygenated and returned to the left heart for distribution. In normal circumstances, the right heart pumps blood into the lungs without any resistance. The lungs usually have minimal pressure and the right heart easily pumps blood through.
However when there is lung disease present, like emphysema
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
, chronic obstructive lung disease (COPD) or pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
- the small blood vessels become very stiff and rigid. The right ventricle is no longer able to push blood into the lungs and eventually fails. This is known as pulmonary heart disease. Pulmonary heart disease is also known as right heart failure or cor pulmonale. The chief cause of right heart failure is the increase in blood pressure in the lungs (pulmonary artery).
Pathophysiology
There are several mechanisms leading to pulmonary hypertension and cor pulmonale:- Pulmonary vasoconstrictionVasoconstrictionVasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
- Anatomic changes in vascularization
- Increased blood viscosityViscosityViscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
- Idiopathic or primary pulmonary hypertensionPulmonary hypertensionIn medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
Causes
- Acute:
- Massive pulmonary embolizationPulmonary embolismPulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
- Exacerbation of chronic cor pulmonale
- Massive pulmonary embolization
- Chronic:
- COPDChronic obstructive pulmonary diseaseChronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
- Primary Pulmonary HypertensionPulmonary hypertensionIn medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
- Recurrent Pulmonary EmbolismPulmonary embolismPulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
- Loss of lung tissue following trauma or surgery
- Pierre Robin sequencePierre Robin syndromePierre Robin Sequence , also known as Pierre Robin Malformation, is a congenital condition of facial abnormalities in humans. PRS is a sequence: a chain of certain developmental malformations, one entailing the next...
- End stage PneumoconiosisPneumoconiosisPneumoconiosis is an occupational lung disease and a restrictive lung disease caused by the inhalation of dust, often in mines.-Types:Depending upon the type of dust, the disease is given different names:...
- SarcoidosisSarcoidosisSarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
- T1-4 Vertebral subluxationVertebral subluxationVertebral subluxation is a term that is commonly used by some chiropractors to describe signs and symptoms of the spinal column. Those chiropractors who assert this concept also add a visceral component to the definition...
- Obstructive sleep apneaObstructive sleep apneaObstructive sleep apnea or obstructive sleep apnea syndrome is the most common type of sleep apnea and is caused by obstruction of the upper airway. It is characterized by repetitive pauses in breathing during sleep, despite the effort to breathe, and is usually associated with a reduction in...
- Altitude sicknessAltitude sicknessAltitude sickness—also known as acute mountain sickness , altitude illness, hypobaropathy, or soroche—is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude...
- Sickle cell anemia
- Bronchopulmonary dysplasia (in infants)
- COPD
Symptoms
The symptoms of pulmonary heart disease depend on the stage of the disorder. In the early stages, one may have no symptoms but as pulmonary heart disease progresses, most individuals will develop the symptoms like:- Shortness of breath which occurs on exertion but when severe can occur at rest
- Wheezing
- Chronic wet cough
- Swelling of the abdomen with fluid (ascitesAscitesAscites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...
) - Swelling of the ankles and feet (pedal edema)
- Enlargement or prominent neck and facial veins
- Enlargement of the liverHepatomegalyHepatomegaly is the condition of having an enlarged liver. It is a nonspecific medical sign having many causes, which can broadly be broken down into infection, direct toxicity, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdominal mass...
- Bluish discoloration of face
- Presence of abnormal heart sounds
- possible bi-phasic atrial response shown on an EKG due to hypertrophy
Diagnosis
In many cases, the diagnosis of pulmonary heart disease is not easy as both the lung and heart disease can produce similar symptoms. Most patients undergo an ECG, chest X ray, echocardiogram, CT scan of the chest and a cardiac catheterizationCardiac catheterization
Cardiac catheterization is the insertion of a catheter into a chamber or vessel of the heart. This is done for both investigational and interventional purposes...
. During a cardiac catheterization, a small flexible tube is inserted from the groin and under x ray guidance images of the heart are obtained. Moreover the technique allows measurement of pressures in the lung and heart which provide a clue to the diagnosis.
Epidemiology
Each year there are about 20,000 deaths and close to 280,000 hospital admissions among individuals who have pulmonary heart disease. The majority of individuals affected by pulmonary heart disease are women less than 65 years of age. Infants who are born with congenital heart disorders (esp. holes in the heart like a VSDVentricular septal defect
A ventricular septal defect is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart.The ventricular septum consists of an inferior muscular and superior membranous portion and is extensively innervated with conducting cardiomyocytes.The membranous...
) are prone to pulmonary artery disease. In infants the earlier the heart disease is treated, the better the prognosis. While pulmonary heart disease is serious, it is much less common than coronary artery disease.
Complications
Blood backs up into the systemic venous system, including the hepatic veinHepatic vein
In human anatomy, the hepatic veins are the blood vessels that drain de-oxygenated blood from the liver and blood cleaned by the liver into the inferior vena cava....
. Chronic congestion in the centrilobular
Hepatic lobule
A hepatic lobule is a small division of the liver defined at the histological scale. It should not be confused with the anatomic lobes of the liver , or any of the functional lobe classification systems....
region of the liver leads to hypoxia and fatty changes of more peripheral hepatocytes, leading to what is known as nutmeg liver
Nutmeg liver
In hepatology, congestive hepatopathy, also known as nutmeg liver and chronic passive congestion of the liver, is liver dysfunction due to venous congestion, usually cardiac dysfunction, i.e...
.
Investigations
- Chest X-RayChest X-rayIn medicine, a chest radiograph, commonly called a chest X-ray , is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures...
- Right ventricular hypertrophy, right atrial dilatation, prominent pulmonary artery, peripheral lung fields show reduced vascular markings. Patients of chronic obstructive pulmonary disease show features of hyperinflation which include widened intercostal space, increased translucency of lung and flattened diaphragm. - ECG - Right ventricular hypertrophy - right axis deviation, prominent R wave in lead V1 & inverted T waves in right precordial leads, Large S in Lead I, II and III; Large Q in lead III, Tall Peaked P waves (P pulmonale) in lead II, III and aVF. All the above features are not found in a single patient but different patients show different combination of these findings.
- Echocardiogram - Right ventricular dilatation and tricuspid regurgitation is likely
Treatment
Elimination of the cause is the most important intervention. Smoking must be stopped, exposure to dust, flames, household smoke and to cold weather is avoided. If there is evidence of respiratory infection, it should be treated with appropriate antibiotics after culture and sensitivity. Diuretics for RVF, In pulmonary embolismPulmonary embolism
Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
, thrombolysis
Thrombolysis
Thrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...
(enzymatic dissolution of the blood clot) is advocated by some authorities if there is dysfunction of the right ventricle, and is otherwise treated with anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
s. In COPD, long-term oxygen therapy
Oxygen therapy
Oxygen therapy is the administration of oxygen as a medical intervention, which can be for a variety of purposes in both chronic and acute patient care...
may improve cor pulmonale.
Cor pulmonale may lead to congestive heart failure
Congestive heart failure
Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...
(CHF), with worsening of respiration due to pulmonary edema
Pulmonary edema
Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
, swelling of the legs due to peripheral edema
Peripheral edema
Peripheral edema is the swelling of tissues, usually in the lower limbs, due to the accumulation of fluids.The condition is commonly associated with aging, but can be caused by many other conditions, including congestive heart failure, trauma, alcoholism, altitude sickness, pregnancy,...
and painful congestive hepatomegaly (enlargement of the liver due to tissue damage as explained in the Complications section. This situation requires diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
s (to decrease strain on the heart), sometimes nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
s (to improve blood flow), phosphodiesterase inhibitor
Phosphodiesterase inhibitor
A phosphodiesterase inhibitor is a drug that blocks one or more of the five subtypes of the enzyme phosphodiesterase , therefore preventing the inactivation of the intracellular second messengers cyclic adenosine monophosphate and cyclic guanosine monophosphate by the respective PDE...
s such as sildenafil
Sildenafil
Sildenafil citrate, sold as Viagra, Revatio and under various other trade names, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension . It was originally developed by British scientists and then brought to market by the US-based pharmaceutical company Pfizer...
or tadalafil
Tadalafil
Tadalafil is a PDE5 inhibitor, currently marketed in pill form for treating erectile dysfunction under the name Cialis; and under the name Adcirca for the treatment of pulmonary arterial hypertension...
and occasionally inotrope
Inotrope
An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions...
s (to improve heart contractility). CHF is a negative prognostic indicator
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
in cor pulmonale.
Oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
is often required to resolve the shortness of breath. Plus, oxygen to the lungs also helps relax the blood vessels and eases right heart failure. Oxygen is given at the rate of 2 litres per minute. Excess oxygen can be harmful to patients because hypoxia is the main stimulus to respiration. If such hypoxia is suddenly corrected by overflow of oxygen, such stimulus to the respiratory center is suddenly withdrawn and respiratory arrest occurs. When wheezing is present, majority of the patients require bronchodilators. A variety of drugs have been developed to relax the blood vessels in the lung. Calcium channel blockers are used but only work in a few cases. Other novel medications that need to be inhaled or given intravenously include prostacyclin
Prostacyclin
Prostacyclin is a member of the family of lipid molecules known as eicosanoids.As a drug, it is also known as "epoprostenol". The terms are sometimes used interchangeably.-History:...
derivatives.
Cases of COPD with chronic corpulmonale present with secondary polycythemia , if severe it may increase the blood viscosity and contribute to pulmonary hypertension. If hematocrit(PCV) is above 60%, then it is better to reduce the red blood cell count by phlebotomies.
Mucolytic agents like bromhexine and carbocisteine help bring out excessive bronchial secretions more easily by coughing.
All patients with pulmonary heart disease are maintained on blood thinning medications
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
to prevent formation of blood clots.
When medical therapy fails, one may require a transplant. However, since the lungs are damaged, both the heart and lungs needs to be transplanted. With a shortage of donors this therapy is only done 10-15 times a year in North America.
Prevention
While not all lung diseases can be prevented one can reduce the risk of lung disease. This means avoiding or discontinuing smoking. Patients with end stage emphysemaEmphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
or chronic obstructive lung disease always end up with right heart failure. When working in environments where there are chemicals, wear masks to prevent inhalation of dust particles.
External links
- Emedicine
- The Merck Manual of Diagnosis and Therapy: Cor Pulmonale