What is Diastolic heart failure
The reasons of the heart-related diseases are many. The present-day stress of work and personal life is no doubt one of the important causes. That apart, the way of living and the lifestyle also sets the tone.
The dietary constituents, the time of eating, the exercises or the lack of the same, weight-related issues are all leading to the same. In the present day era, heart-related risks are not restricted to any particular age group.
There was a time when the middle-aged and the elderly were more susceptible to this. But this does not hold true any longer. In today’s times, anyone and everyone can be part of the risk.
There are different types of heart-related ailments. One of the potent and common forms is diastolic related to heart failure. The term basically relates to the mechanism through which the heart fills.
In medical terms, it can be defined as the process by which the Left Ventricle gets filled with blood due to the result of the pressure levels between the left atrium and the left ventricle.
During this process, in some scenarios, there is a suction that happens when the left ventricles expand rapidly. This means, there are stages of passive and active blood filling.
In between these stages, there is a phase of slow filling which is known as diastasis. In layman terms, this forced relaxation of the Left Ventricular (LV) is known as diastasis.
It leads to stiffness of the LV and a higher level of pressure filling.
A brief word can be mentioned about Systolic dysfunction as this is a condition caused by the effectiveness or the lack of the same when the heart fills the body with blood. The main reason again is the case is related to the LV.
However, the functionality is the weakness of the same as it expands in size. This makes it difficult to pump the blood to the body parts.
The diastolic dysfunction can lead to heart failure and in many cases is fatal. The symptoms are more or less similar to any form of heart disease and attack.
These include breathlessness problems; pain the left arm or shoulder, dizziness bouts, lack of appetite and a tendency to urinate more at night.
The diagnosis is normally done through a method known as Doppler Echocardiography.
This process takes the route of ultrasonography and measures the speed and direction of the flow of blood through what is known as the Doppler Effect(the measure of the change in the frequency of a wave in proportion to the observer moving in tandem to the wavelength).
As per the suggested medicinal practices, the treatment of the diastolic heart disease is done through the normal ways of bringing blood pressure under control, reducing the congestion levels of the body, the contraction of LV skeletal muscle due to component growth, keeping the arterial conditions at normal level as much as possible and controlling fast heartbeat rates – known as Tachycardia.
The control of urine flow is the proper treatment for keeping the congestion level in the body under control and medications that prevent fast beats like beta blocker is also suggested at this stage.
This is done through the use of what is known as beta-blocker category medication specially used to control Tachycardia. A high level of blood pressure often results in stress and Hypertension.
This leads to diastolic nonfunctionality. The preferred way to treat it is through the use of Angiotensin receptor blockers and enzyme inhibitors.
However, there is still no evidence from conclusive trails, as of now, on its usage. The final evidence from these clinical trials may give the much needed accurate information that will help in formalizing the therapy.
This will enable to move from instinctive treatment. The outcome will be based on real-life scenarios like reduced mortality rate and perceptible improvement in the daily health standards of the affected persons.
A more detailed analysis:
Heart-related disease remain a major cause of worry across the world. Even in the most developed countries like the USA, almost 5 million people are affected annually by related ailments. Of course, most of them are in the age group of 65 years and above.
However, the age group of 25 to 40 is also slowly but surely becoming sad victims to heart-related issues. It is further noticed that almost 40% of the victims suffer fatal attacks if it is an advanced heart ailment and about 8 to 10% are susceptible to mortality in the case of mild heart diseases.
In all cases, this may not happen immediately but within a span of 6 to 7 years. This, on the contrary, makes it even more dangerous as patients have the tendency to get relaxed over the years when they recover.
If this is the scenario in the USA, then, in the lesser developed countries, the statistics can be well imagined!
There are 2 main reasons for heart-related ailments and diseases. The first is related to the reduction or contraction of the heart and this falls in the systolic heart disease.
The second is related to the impaired ability of the heart in its relaxing functionality and this comes in the category of diastolic heart diseases or failures.
Data collection and observation till now have found that a range between half and one-fourth of patients get affected by the former. In the case of the latter i.e.diastolic, the elderly and women are prone to this diastolic heart failure.
The mortality rate is much lower in the case of diastolic heart patients but they form a higher proportion of people affected by this form of heart failure. The in-patient admission numbers are also the same in both cases.
All these factors pint out to one thing and that is the fact that diastolic heart diseases are a dangerous and increasing source of threat among the human population and carry with them god risks of mortality or hospitalization ate the bare minimum level.
It is necessary to understand more about this condition and carry on with more levels of clinical research so that necessary prevention can be put in place and proper treatment can be carried out according to the situation.
The various reasons for the occurrence –
Biological process disorders and pathology issues:
By itself, the Diastole is the return of the heart towards a stage of relaxation. This is not the cause of worry but the deviation from the normal pattern is the main reason.
This is also the process by which, the blood flow in the heart goes through its normal channels. In the entire phase of diastole, there is an imbalance at the desired level of heart pressure and volume parameters.
There are four distinct stages to the cycle of relaxation. The first is isovolumetric relaxation which happens when the aortic valve is closed and the mitral valve is opened (this valve allows the flow of blood from the left atrium to the LV).
The second is the filling that happens once the mitral valve is opened. Next is the stage of low flow during the middle of diastole and the last is the filling of the ventricles. This happens, post arterial contraction.
For those patients who have only diastolic heart issues, heart functionality is at the desired level required by body metabolism. But this happens at an elevated pressure level of diastolic.
There is an impaired relaxation in the LV and this makes it stiff. Transfer of this elevated pressure of the LV into the pulmonary circulation causes issues like congestion and labored breathing. These are the typical symptoms of a heart attack.
There are several factors that lead to the diastole heart condition. These include the rate of heartbeats, tissue enlargement, artery built up the blockage, expansion of the hearts chamber when filled with blood – also known as compliance, heart muscle coordination of the wall.
This is the common reason for heart failure worldwide and these days accentuated to a large extent by the increasing work and financial related stress.
It is also common to see chronic hypertension resulting in LV muscle and tissue enlargement and more connective tissue content. Both these lead to a cardiac reduction of compliance.
The enlarged or otherwise also known as hypertrophied ventricle has a much-elevated level of pressure and volume connectivity relationship.
The end result is that even a minute increase in LV end-diastolic volume causes a disproportionate increase in the LV diastolic pressure at the end level. The reasons may be different like excessive body exertion physically.
It is also known as artery blockage. This happens when the calcium ions flow into the sarcoplasmic reticulum of the muscle cells through ventricular relaxation.
This leads to the delinking of the myosin actin cross-bridges. The deficiency in the amount of oxygen reaching the tissues also known as Hypoxia slows down this delinking process.
This is done by changing the structural balance of the adenosine triphosphate–to–adenosine diphosphate ratio. This can be one of the potent causes of diastolic heart failure.
The existing heart rate:
This is a very important indicator of human health and any deviation or aberration of the same has to be taken seriously. Corrective measures have to be put in place without any delay.
In the simplest of language, the heart rate is the measurement of heartbeats within a time frame of one minute. The speeds as well as the rhythm, both are important.
In body functional terms, the heart rate sets the time that permits, perfusion, ventricular relaxation as well as the ventricle blood filling also known as diastolic filling.
This is dependent on ventricular relaxation especially the early part. An increased heartbeat rate affects the diastolic function on several counts. It reduces the overall ventricular perfusion and it also increases the oxygen intake of the heart.
This leads to incomplete relaxation as the heart is in a stiff mode due to the strain of more oxygen consumption. It is recommended that people having diastolic heart conditions reduce their physical exercises as it is difficult for them to cope with fast heart rates.
The deviation in heart rhythms happens when the electrical impulses are released from the top chamber of the heart – the left and the right atria, in an unorganized manner.
The top chamber is also known as the atria. Whenever this happens, the atria twitches as an aftermath of the irregular beat. In medical terms, it is called Atrial Fibrillation.
It is one of the major reasons for stroke or heart attack. When this inconsistent heartbeat occurs, there is a high end-diastolic pressure that is created on the ventricle.
It also results in loss of aerial contraction resulting in heart failure. An important thing to prevent Atrial Fibrillation is to control the ventricular rate.
The ventricular load imbalance:
The systole is that particular part of the heartbeat where the heart muscle contracts. This allows the blood to flow from the chamber to the arteries.
It is defined by the time period. During the systole, the blood pressure normally increases. This happens in the following manner-- At the end of the systole, there is left behind, a small residual of blood in the left ventricle.
When this residual volume increases, it impedes the elastic heart recoil, the heart relaxation process. It also results in the development of a negative pressure gradient from the ventricle to the atria. The net result is that diastolic fillings get weakened.
With age, the tissue wear and tear becomes more common. Like all other body organs, the heart and its components also get affected. With age, the elastic fibers also get loosened.
The Collagen i.e. the protein inside the skin and the tissues get cross-connected. This means the fibrils in the Collagen gets linked to the nearby fibrils.
This results in ventricular deviation and this means that patients having diastolic dysfunction are heavily in the risk of being more prone to tachycardia, Atrial Fibrillation, and hypertension.
Understanding the symptoms –
Many of the symptoms that lead to heart failure are not common and often co-related to other diseases or even body condition. The most common symptoms are breathing difficulties, fatigue over minor excretion, inability to do heavy physical exercises, chest pain, etc.
These are normally visible in other diseases like Asthma, hypothyroidism, obesity and other types of pulmonary diseases. All these symptoms are prevalent in systolic heart failure as well.
As of now, the diagnostic methods of diastolic heart diseases are still undergoing evaluation and exclusivity of any symptom has not been assigned.
The methods used -
Cardiac catheterizations a rather common if not accepted way of measuring the impaired form of ventricular relaxation but there are major limitations to this.
The total benefits vis a vis its side effects and other cost factors are making the medical industry look at it in a slightly wary manner and it has not been given the complete go-ahead to date.
The advantage is that it gives a fairly proper measure of ventricular diastolic pressure.
The more accepted rom is Doppler echocardiography and this has assumed a good amount of significance, especially in the non-invasive form of cardiology tests done without any form of needles or fluid insertion into the body.
It is used and accepted to a good extent to verify the level of diastolic heart related issues. To take an example, ventricular stiffness is something that can be measured through the concept of TAU.
This is the level of LV decay that can be ascertained during the phase of isovolumetric relaxation.
Another main advantage of Doppler echocardiography is that it has proved effective in understanding the characteristics and features of diastolic trans-mitral valve blood flow.
Through this, the highest velocity of blood flow is calculated during the early diastolic filling and the stage of contraction of the artery. This is expressed in the form of a ratio.
The early diastolic filling is known as E-Wave and the atrial contraction is known as A wave. In normal circumstances, the E-Wave is higher to the A-Wave and it is 1.5 times that of the latter.
At the early stages of diastolic related issues, this ratio changes. This is because of the relaxation impairment due to heart stiffening. As the LV pressure rises, the E to A wave ratio crosses beyond 2.0.
The drawback of this method is that it is a sort of “restricted prognosis”. This does not deliver the best of the results.
There are certain other diagnoses done in myocardial velocities that have a tendency to predict not too accurate results. It also gives an elevated filling of pressure. Another limitation is that such velocity measurement is fine in certain cases but it does not help in Atrial Fibrillation.
However, at the end of the day, the pros outweigh the cons. The Doppler echocardiography is fairly well-practiced and it provides crucial information about chamber size, heart anatomy, valvular function, muscle and tissue expansion, Ischemia.
It is also a valuable tool for the doctor to understand or rule out any potential symptoms like hypertension, exhaustion, chest related pains, and other pericardial ailments.
Another useful diagnosis media is the Serum B type natriuretic peptide to evaluate the diagnosis of heart related issues, especially for those with breath shortness problems known as dyspnea.
However, a limitation of this method is the inability to differentiate between diastolic and systolic heart failures in mixed patients having both the symptoms.
The European Study Group made certain concerted efforts to establish the diagnosis symptoms of diastolic heart failures. They categorized it into three parts namely – the presence of left ventricular systolic function.
This can be mild or slightly above the mild. The second is the evidence of normal heart symptoms sign. The third is the presence of diastolic stiffness and diastolic distensibility on the LV.
However, the major limitation of this approach is that it was nonspecific and the medical fraternity found it difficult to accept it in real-life practice.
There were also constraints in getting proper evidence in terms of relaxation deviation in daily practice and examination of patients.
Another research team after several studies and evaluations presented three possible and probable conditions of diastolic heart failures based on the conditions of certain possible symptoms.
They were listed down as the following – clear and comprehensive evidence of heart failure (issues, presence of objective evidence of LV systolic function that manifests itself within not more than 72 hours of the heart issues surfacing, the presence of clear cut objective evidence of LV dysfunction through cardiac catheterization.
In the event of all the three conditions being present, it will be confirmed that diastolic heart failure is present. If there is evidence of the first two conditions being conclusively present then the diagnosis is more or less correct.
If only the first condition is present and the second and third conditions are partially evident, then the diagnosis of diastolic heart failure is considered as a possibility.
As of today, there is no standardization of methods adopted to confirm the symptoms of diastolic heart dysfunction. It is a combination of the different tests and methods namely - Cardiac catheterization, Doppler echocardiography, Serum B type natriuretic peptide.
The doctors and the lab specialist use each method according to the more prevalent and accepted one in their method of practice. Each method has its own limitations and advantages.
The suitability may be more of the case specifics. The research work on the same is continuing and the aim to develop a non-specific approach remains the top objective of study groups and research specialists.
At the end of the day, there should be an objective approach for a pinpointed confirmation of diastolic heart dysfunction and it has to be accepted and standardized in a wide sense.
At this particular juncture, the treatment guidelines of diastolic heart failure are yet to be defined to the same extent that systolic heart failure issues are being treated.
One reason for this may be due to the fact that predecessor symptoms are also in the stage of being defined. The existing mode of procedure in treatment is also linked to the diastolic heart disease-oriented evidence.
This includes the various elements of all types of cardiovascular diseases, biological process disorders and pathology issues, cumulative knowledge on heart related ailments, focus group, and expert opinion studies.
So far, none of the recommended treatment processes has been ratified by Randomized Controlled Trials (RCT). The RCT can be defined as a medical experiment wherein the aim is to reduce the impact of the bias-related factors.
At the same time, it tests the result orientation of new techniques. The behavior of subjects to a measured response is also analyzed. As of now, most of the guidelines have come from the Institute for Clinical Systems Improvement (ICSI and the American College of Cardiology (ACC).
This will continue to be so till the acceptance and strictures come from RCT. The continued research and academic study on the subject also go on.
It is also known as Non- Pharmacologic approach. Every heart related disease has its roots in the lifestyle and other daily habits with eating forming the main constituency.
Most of the heart and all forms of cardiovascular diseases have been brought under control through lifestyle modifications. The main factors to be taken care of are a reduction of obesity, strict control on eating with reduced carbohydrates and fats and more intake of proteins, the timing of eating, stoppage on habits like smoking and drinking, regular body exercise on a daily basis.
This should bring to minimal level conditions like high blood pressure, cholesterol, diabetes, and hypertension.
This is the direct opposite of the earlier method. It is also known as Pharmacologic treatment or medicinal method.
The infusion of medicines aims to control and eliminate if possible the conditions of high blood pressure, control of fast heartbeats, also known as Tachycardia, congestion reduction, controlling the increase of skeletal muscle tissues also known as Hypertrophy.
Every medicinal treatment is totally based on evidence of diagnosis and objective evidence obtained. There are different medications for different needs.
Diuretics or water pills are used to reduce congestion in the body. This helps in the proper outflow of urine. To control the Tachycardia, beta-blockers is used.
This is especially necessary to treat the more aged patients who are suffering from diastolic heart issues. To reduce the Hypertrophy or muscle tissue enlargement, there is something known as Angiotensin-Converting Enzyme (ACE) inhibitors.
This also helps to reduce blood pressure and other cardiac problems. The Digitalis medicines can be used for the treatment of all congestive heart failures and steadying heart rhythm. It helps to streamline the blood flow in the body.
The Myocardial revascularization surgical process is suggested to patients having a history of ischemic heart disease, coronary heart disease and problems of cardiac stenosis i.e. basically a thickening of the heart.
Another important form of revascularization is angioplasty. Most of the medications worldwide are in accordance with the recommendations of the ACC.
There is a controlled recommendation use of calcium channel blockers because it does the function of controlling the blood pressure and dilates the coronary arteries.
But this should be used in caution over patients having a combination of systolic and diastolic heart issues.
It should be noticed that all medicinal treatment has to be given based on patient history and their reactions to the type of treatment.
It has to be a combination of case and patient-specific treatment. The studies and research on many drugs like ACE and calcium blockers and Digitalis are continuing and evolving.