Cardiorenal Syndrome (CRS) refers to a group of medical conditions, characterized by the coexistence of renal and cardiac dysfunctions, which is having a growing incidence. Read on to get detailed information about the disorder, including its causes, symptoms, diagnosis and treatment.
A universally acceptable definition of this syndrome is yet to be recognized. However, CRS can still be defined as a disorder that affects the heart as well kidneys – leading to a chronic or acute dysfunction in either of the organs, which affects the other organ in a similar way. The condition can be understood better by considering its various types.
Both the heart and kidneys are responsible for maintaining the regular blood flow, involving many pathways or channels. If performance of the either organ is affected, the other organ simultaneously suffers a failure too.
CRS has been divided into 5 subtypes:
In this type, heart functions deteriorate acutely and lead to renal malfunction. Renal functions might deteriorate in patients hospitalized with ADHF or acute decompensated heart failure plus acute coronary syndrome, turning fatal.
Type 1 has been functional in defining CRS.
This is a common syndrome in patients with chronic cases of kidney disease which affects and complicates any chronic heart ailment.
This is the most poorly deciphered form and there is very less prevalence of this syndrome. It is documented that acute kidney injury may result in acute heart disorder.
This is a condition in which Chronic Kidney Disease or CKD leads to reduced cardiac functions. It is related to heart dysfunctions, like left ventricular diastolic dysfunction, resulting from CKD.
This syndrome is also known as secondary CRS – a condition in which both kidney and heart suffers dysfunction (chronic or acute) due to disorders like systemic lupus erythematosis, sepsis and diabetes mellitus.
Renal and cardiac dysfunctions may also arise due to chronic or acute systemic disorders. These include diabetes and poorly controlled hypertension, which are often found to be the main causes of this disorder. There are various other causes of the disease which differ on the basis of its type that one is found to suffer from.
Glomerular filtration rate or GFR is not correlated with serum creatinine and this should be considered during diagnosis of CRS. Measurement of serum creatinine can be misleading as far as prognosis is concerned. It has been observed that a lot of patients with aggravated Congestove Heart Failure have reported of lower GFR though many of them had normal serum creatinine levels. The determination of GFR can help in deciding the treatment strategy and should be a part of the initial diagnosis. Since determination of serum creatinine level is not trustworthy, it is safer to measure GFR by employing Cockcroft-Gault formula.
However, even Cardiac Output (CO) is not considered to be dependable for examining the seriousness of the disorder. It often shows to be normal, which makes it highly misleading in some cases of CRS.
It is challenging to devise a treatment plant for patients suffering from CRS. The pathophysiology of CRS varied and complicated which makes it more difficult to be treated. A single treatment plan cannot be pinpointed for resolving the disorder as patients have distinct medical history and associated risks. Inclination towards usage of ultrafiltration, AVP antagonists and other novel therapies has increased as standard therapies are being opposed. Some management strategies have been listed below:
CRS is also quite prevalent amongst children with heart failure. This worsens renal function, which in turn increases risk. In critically ill children, it might become morbid even during hospitalization. CKD is a grave illness which might turn devastating with more children becoming obese. Childhood obesity has been connected with Cardiorenal Syndromes, increasing rapidly. Type 2 Diabetes mellitus, impaired glucose tolerance and even hypertension has been linked to it.
This is an extremely fatal disorder caused by the association between chronic kidney and heart failure along with anemia. In this syndrome, there is an increase in anemic state. It is also marked by severe impairment of the functions of the other two organs. This has been a subject of study to determine the role played by each other in the disorder.
There is insufficient data about the pathophysiology of CRS. Renal functions may suffer due to Congestive Heart Failure or CHF which reduces Cardiac Output (CO). This, in turn, reduces renal perfusion resulting in deterioration of renal functions.
Patients diagnosed with ADHF have also shown decline in renal functions though their LVEF is protected which regulates blood flow. This has led to more studies about CRS mechanisms which take into consideration, SNS overactivity, RAAS or the rennin-angiotensin-aldosterone system or oxidative stress beside few others.
On the onset of CRS, it becomes very difficult to suspend it, leading to severe consequences including death. Here are some probable preventive measures of the subtypes, which might throw some light on it.
Continuous Renal Replacement Therapy or CRRT might help protect in many ways. It removes nitrogenous wastes, helps in euvolemia and assist in working of the kidneys in a critical period.
Controlling diabetes and hypertension might help to a great extent in this type of CRS. Some believe that microalbuminuria can be reduced by the use of fibric acid derivatives in patients diagnosed with CKD.
By avoiding excess increase in body’s plasma volume, cardiac decompensation can be checked in the type 3 Cardiorenal Syndrome.
By following treatment guidelines for CKD, mineral anomaly and anemia can be managed. Some of the ways to prevent it are by using glycemic control, blood pressure control, therapies and RAAS blockers.
For preventing this CRS type, no sure shot methods can be indicated. Certain strategies can be adopted like intravenous fluid or pressor agents to control hypotension, but that might not be sufficient to avert acute kidney or cardiac injury.
The condition is not found to have a very good prognosis. It is the presence of two fatal disorders which has life-threatening consequences for CRS sufferers. Patients diagnosed with Chronic Renal Failure have the greatest risk of acquiring cardiac diseases which increases the chances of morbidity than the masses. More than 40 percent of patients with last stage renal diseases die as a result of cardiac issues. Renal functions suffer badly due to the treatment of heart failures.
Unless timely attended, Cardiorenal Syndrome can have fatal consequences for its sufferers. Get early medical assistance as soon as you spot abnormalities in cardiac or renal function in yourself or any of your family members.