Cardiorenal syndrome is a condition that affects the heart and kidneys at the same time. The syndrome is often referred to by the abbreviation KRS. Chronic or acute impairment of the function of one organ results in impairment of the other. The term originally comes from the therapy of heart failure. In this case, heart failure was limited by impairment of kidney function.
What is cardiorenal syndrome?
In cardiorenal syndrome, the heart and kidney impair each other’s function. The interactions between the two organs vary depending on the individual case. However, the disease can be divided into different types. The term cardiorenal syndrome is used to distinguish individual manifestations when a disease of the heart leads to an impairment of the function of the kidney. The term renocardial syndrome is used when disease of the kidney affects the heart. In addition, the term includes the condition in which an underlying disease causes simultaneous damage to the heart and kidney. Assured data on the incidence of cardiorenal syndrome are scarce. Persons suffering from stable heart failure are affected by chronic kidney failure in 20 to 60 percent of cases. If heart failure decompensates acutely, renal failure occurs simultaneously with almost 70 percent increased probability. If terminal renal failure is present, heart failure is the most common cause of death.
Causes
In the development of cardiorenal syndrome, the heart and kidney affect each other. Heart failure impairs kidney function, whereas kidney failure impairs heart function. Cardiorenal syndrome is divided into four types. Types 1 and 2 include cardiorenal influences. Here, heart failure leads to worsening renal function. The reasons for this are not yet fully understood. Originally, the explanation was that the kidneys receive a poorer blood supply because the pumping function of the heart is reduced. The resulting kidney failure is also referred to as prerenal. However, various studies have been unable to demonstrate any correlation between the severity of renal impairment and cardiac pump function. Instead, it is mainly those patients in whom increased pressure has been measured in the veins that feed into the heart who suffer kidney failure. For this reason, physicians now assume that the backlog of blood in front of the heart plays a greater role. In types 3 and 4, renocardial influences are more prominent. Kidney weakness causes an increased load on the heart, since the heart has to transport a greater amount of blood. As a result, heart failure gradually develops.
Symptoms, complaints, and signs
Cardiorenal syndrome manifests itself through various symptoms, depending on the type and stage.
- Type 1 is characterized by acute heart failure associated with acute renal failure. In addition, cardiac arrhythmias, myocarditis, and cardiogenic shock often occur.
- Type 2 is characterized by chronic heart and kidney failure. Also, defects in the heart valves and a so-called cardiomyopathy are possible. At
- Type 3, acute renal failure occurs in combination with acute heart disease. In some cases, cardiac arrhythmias, acute coronary syndrome or pulmonary edema also occur. Renal failure can be induced by contrast media. Also, an interstitial nephritis as well as a urinary stasis can form.
- Type 4 is characterized by chronic renal and cardiac failure. Glomerulonephritis and cystic kidneys are also possible.
- In type 5, there is either acute or chronic heart failure associated with acute coronary syndrome and acute renal failure. Even sepsis and diabetes mellitus and amyloidosis are possible in this type. It should be noted that a clinically exact classification is often impossible. Chronic heart failure and chronic renal failure often occur together because they are predominantly due to the same risk factors.
Diagnosis and course of the disease
Cardiorenal syndrome is diagnosed using established diagnostic criteria regarding renal and cardiac disease. Presenting heart failure is diagnosed using the criteria of the so-called European Heart Association. Acute renal failure is usually subdivided and diagnosed using the RIFLE criteria, while chronic renal failure is diagnosed using the KDIGO or KDOQI criteria. In principle, the initial focus in the diagnosis of cardiorenal syndrome is a discussion of the patient’s medical history, which provides the attending specialist with guidance on further diagnostic and therapeutic procedures.
Complications
In most cases of this syndrome, various complaints occur. As a rule, the affected persons suffer from kidney and heart complaints in this case. The quality of life is thereby greatly reduced and the resilience of the affected person drops just as enormously. In the worst case, complete kidney failure can result, making the patient dependent on a donor kidney or dialysis. Furthermore, the patients suffer from disturbances of the heart rhythm and can, in the worst case, suffer cardiac death. Life expectancy is reduced by this syndrome if no treatment occurs. Similarly, the lungs may be affected, so that patients also suffer from shortness of breath or gasping for breath. It is not uncommon for diabetes to occur as well. Furthermore, the various complaints can also lead to psychological complications or depression. These can be treated by a psychologist. It is not possible to treat this syndrome causally. For this reason, treatment is exclusively symptomatic. In this case, life expectancy may be limited if necessary. In acute emergencies, organ transplantation may be necessary.
When should you see a doctor?
When the typical symptoms of cardiorenal syndrome are noticed, a physician should be consulted. The affected person should seek medical advice if he or she feels unwell for several days or weeks. Symptoms such as urinary retention or breathing difficulties indicate a serious condition that requires clarification by a physician. Medical advice must be sought at the latest when kidney complaints occur. The affected person should consult the family doctor or a nephrologist. Early diagnosis improves the chances of a speedy recovery. If no treatment is given, cardiorenal syndrome progresses and causes symptoms such as kidney failure or sepsis. At this stage, emergency medical care is needed. The affected person must be taken immediately to a doctor’s office or hospital, as there is an acute danger to life. After initial treatment, the patient must consult other physicians to rule out or treat any secondary conditions. Individuals suffering from heart failure or renal insufficiency are particularly susceptible to the development of cardioarenal syndrome and should seek immediate medical attention if the warning signs are mentioned.
Treatment and Therapy
Cardiorenal syndrome is treated according to the type and symptoms shown. Central is always to treat the underlying diseases and minimize possible risk factors. In the hospital, affected individuals are treated primarily for acute fluid overload (hydropic decompensation). Edema of the limbs, shortness of breath due to pulmonary edema or pleural effusions are indicative of fluid overload. To support renal function, fluid balance must be regulated. If there is an excess, the amount of fluid drunk must be restricted. It is also possible to reduce fluid overload by so-called diuretic or diuretic agents.
Outlook and prognosis
In addition to a detailed medical diagnosis and resulting treatment plan, the affected person can also become active himself. To what extent this is possible depends largely on the cause of the disease and the chosen medical treatment. Avoiding physical activity combined with bed rest helps relieve symptoms regardless of the cause. Dietary changes coordinated with the physician and abstaining from addictive substances can reduce the medication dose and relieve the cardiovascular system. To improve kidney function, it is necessary to optimize fluid balance.If excess fluid is present, fluid intake must be reduced in consultation with the physician. Foods such as asparagus or carrot juice support this effect, as do any diuretics that may have been prescribed. If this does not have the desired effect, temporary dialysis therapy can be discussed with the physician. This stabilizes the condition of the kidney failure until the medical treatment of the heart failure is successful. If, on the other hand, there is a lack of fluids, an increased intake of fluids in the form of water, herbal and fruit teas or fruit spritzers has a supporting effect. Naturally, diuretic foods should be avoided. Since both too much dehydration and too much fluid intake lead to a significant worsening of symptoms, regular checks of kidney function and electrolyte balance are essential and self-therapy should be adjusted accordingly to these values.
Prevention
Preventive measures for cardiorenal syndrome are closely related to the prevention of cardiac and renal insufficiencies. Lifestyle risk factors should be minimized. Regular checkups with a physician provide early indications of deterioration in organ function of the heart and kidney.
Follow-up care
In most cases, follow-up care options for this syndrome are severely limited. Those affected are primarily dependent on a rapid diagnosis with subsequent treatment to prevent further complications and further worsening of symptoms. As a rule, self-healing is not possible, as this is a genetically determined disease. If the patient wishes to have children, genetic testing and counseling should be performed in any case to prevent the recurrence of the syndrome. In general, those affected by this disease are dependent on regular checks and examinations by a doctor. In particular, the kidneys and the heart must be checked especially well and regularly in order to detect damage at an early stage. Likewise, the affected person should not drink too much in order not to put unnecessary strain on the kidneys. Stressful or physical activities should also be avoided in this disease to prevent shortness of breath. In most cases, no further measures of a follow-up are necessary. Whether there is a reduced life expectancy of the affected person due to this syndrome cannot be universally predicted in this case.
What you can do yourself
In any case, cardiorenal syndrome requires comprehensive medical clarification and treatment. What measures those affected can take themselves in addition depends, among other things, on the cause of the symptoms and the medical treatment. In principle, the symptoms of the disease can be alleviated by rest and bed rest. In the case of shortness of breath or edema of the limbs, medicinal preparations are also recommended, which can be supported by remedies from natural medicine. Those affected should talk to their doctor about this and draw up an individual treatment plan. A change in diet also makes sense. Patients should eat a healthy diet and avoid stimulants such as alcohol and nicotine. To support kidney function, patients should drink enough fluids. In addition to mineral water, herbal tea and diluted fruit spritzers are also recommended. If there is an excess, the amount drunk must be reduced. In severe cases, diuretics must be taken. Natural remedies such as asparagus or carrot juice can also promote urination and thus help to alleviate the symptoms. If these measures have no effect, the symptoms must be taken to a doctor.
