Diastolic Heart Failure

The heart's pumping cycle has 2 phases:
 
Diastole
(pronounced : die ass tuh lee)
the heart muscle relaxes and fills with blood
 
Systole
(pronounced : sis tuh lee)
the heart muscle contracts (squeezes) and pumps blood out into the body

 
updated July 5, 2006 - People think of heart failure as a condition where the heart does not pump out enough blood. That is called systolic heart failure. However, many CHFers have a different kind of heart failure - caused when the heart does not fully relax, so it does not fill properly with blood. This is called diastolic heart failure. This page is about diastolic heart failure or DHF.
     In mild DHF, SOB and fatigue usually only happen during stress or activity. More severe DHF causes many of the same symptoms that systolic heart failure or SHF, causes.
     A person with DHF has high pressures in the arteries of their lungs - pulmonary pressure. Their heart's pumping chambers may not be enlarged and their ejection fraction may be normal, but they still have the same nasty symptoms as a person with SHF.
      In people with diastolic heart failure, Toprol-XL may be a better beta-blocker choice than Coreg. Too-low blood pressure can be a real problem for DHF patients. Toprol-XL does not lower blood pressure as much as Coreg.

Causes of diastolic heart failure 

Diagnosing diastolic heart failure 

How to always diagnose DHF accurately is uncertain but a correct diagnosis is important. Some guidelines propose that 3 requirements be met to make the call:

  1. symptoms or signs of CHF
  2. normal systolic function
  3. abnormal diastolic function

There are some situations where symptoms alone may lead to a misdiagnosis. This is especially true in older patients who get short of breath mainly because they have very poor physical fitness. It can also happen with non-heart-related shortness of breath such as with lung disease. So diagnosing DHF requires some signs or symptoms of CHF like lung congestion, edema, raised jugular vein, etc. You do have to rule out problems like mitral valve disease and and lung disease.
     DHF cannot usually be distinguished from SHF by patient history, physical exam, x-ray, and EKG alone. Diagnosis requires an estimate of LV size and EF. These measurements can be made using echo, MUGA, or cath. Really, DHF diagnosis is a matter of ruling out other possible causes in patients seeming to have heart failure but who have normal heart size and EF.
     Since echo does have limits for spotting DHF and cath is invasive, one trial studied whether the BNP blood test could help spot diastolic heart failure. That study is shown on the BNP Test page. It turns out that a quick BNP test can help a doctor diagnose DHF.

Diagnosis: Systolic versus diastolic heart failure
   Systolic Heart Failure - Reduced EF 
30 patients
 Diastolic Heart Failure - Normal EF 
20 patients
Symptoms
 Shortness of breath on exertion 85% 96%
 Waking at night short of breath 55% 50%
 Difficulty breathing except upright 60% 73%
Physical Examination
 Jugular vein swollen 35% 46%
 Sounds in lungs 72% 70%
 Point of maximum impulse 50% 60%
 S3 45% 65%
 S4 45% 66%
 Enlarged (congested) liver 15% 16%
 Edema 30% 40%
 Heart enlargement on chest x-ray 90% 96%
 High pulmonary (lung) pressures 75% 80%

How common is DHF? 

As many as 33% of patients with obvious heart failure and a normal EF may have DHF. Risk of DHF increases with age:

  1. 15% in patients under 60 years
  2. 35% in patients 60 to 70 years
  3. 50% in patients over 70 years old
Mortality 

Prognosis of patients with DHF is better than for SHF. Annual mortality for DHF is about 5 to 8%, while it is about 10 to 15% for SHF. In healthy people of the same age, mortality is about 1%. In DHF patients, prognosis is also affected by cause. When CAD is not the cause, annual mortality is much better, at about 2% to 3%. Age also affects risk of death. The 5-year mortality rate in DHF patients is:

  1. 25% in patients under 60 years old
  2. 35% in patients 60 to 70 years
  3. 50% in patients over 70 years old
Complications 

The complication rate is about the same as for SHF patients. DHF causes frequent outpatient visits and hospital admissions. The one year readmission rate is almost 50% in DHF patients.

Treatment           

Treatment guidelines for systolic heart failure are based on large, properly done trials. Unfortunately, no such trials exist for DHF. So guidelines come from small trials, a doctor's experience, and his understanding of the disease. The general approach to treating DHF has 3 main steps:

  1. Treatment should reduce symptoms, mainly by lowering pulmonary pressure. Ways to reduce pressure include reducing heart size, maintaining good pumping in the heart's upper chambers, and slowing the heart rate.
  2. Treatment should target the underlying cause if possible. For example, high blood pressure should be controlled, remodeling should be reversed, the aortic valve replaced if necessary, and ischemia treated by increasing blood flow to the heart and reducing its need for oxygen
  3. Treatment should target the bodily systems changed by the disease, mainly neurohormonal systems
Drug Therapy - General Principles 

With some exceptions, many of the drugs used to treat systolic heart pressure are also used to treat diastolic heart failure. However, the reason they are used and the dose may be different for DHF.
     For example, in DHF beta-blockers are used to make filling the heart with blood take longer, and to change the heart's response to exercise. In SHF, beta-blockers are used to increase pumping power and reverse heart remodeling. Diuretic dose for DHF is usually much smaller than for SHF. Calcium channel blockers have no place in SHF treatment but may help DHF.
     The first step in treating DHF patients is to reduce lung congestion. You do that by lowering pulmonary (lung) pressure. This has 3 steps:

Reduce heart size
At first, heart size can be reduced by restricting fluid and sodium intake, by dialysis or filtering the blood, plasmapheresis, and diuretics. Relaxing (dilating) the blood vessels using nitro or morphine is effective but should be started at low doses to avoid low blood pressure. Low blood pressure can be a real problem in DHF patients. Long-term treatment should include small to moderate diuretic doses, mild doses of long-acting nitro, and restricted sodium intake. Aldactone (spironolactone) may be effective long-term because it suppresses the RAS. ACE inhibitors and ARBs reduce fluid retention and oxygen demand.
 
Make the heart's chambers beat together as a team
The second step in lowering pulmonary pressure is to keep the heart's upper chambers (atriums) beating properly. Atrial fibrillation is poorly tolerated in DHF patients because it increases diastolic pressures, causing lung congestion and low blood pressure.In patients with a-fib, restoring normal rhythm should be a priority. Patients who need a pacemaker should have atrial pacing as well as ventricular pacing.
 
Slowing the heart rate
The third step in lowering pulmonary pressures is to slow the heart rate. This gives the heart more time to relax so it can fill with blood. Fast heart rate is poorly tolerated in DHF patients because rapid heart rate:
  1. increases the heart's oxygen demand and reduces blood flow to the heart, causing ischemia even without CAD
  2. prevents full relaxation of the heart muscle, which raises pressure and reduces the heart's flexibility
  3. shortens the heart's relaxation period, making it incomplete, which reduces the amount of blood pumped per beat

For these reasons, most doctors use beta-blockers and calcium channel blockers to slow the heart rate a lot in DHF patients. However, slowing the heart rate too much can reduce cardiac output despite better filling. This is why DHF patients need very individualized treatment. An initial goal might be a resting heart rate of about 60 beats per minute.
     Beta-blockers and calcium channel blockers increase the time it takes the heart to fill with blood. This helps keep pulmonary pressures low. However, these drugs also directly reduce the heart's ability to relax by their effects at the cell level. It's a tricky balance to strike in DHF patients. The overall effect of these drugs in DHF patients is improved symptoms.
     The long-term effect of calcium channel blockers on diastolic heart failure patients is unknown. All calcium channel blockers except amlodipine increase mortality in patients with systolic heart failure.

 Nebivolol Helps CHF Seniors with Normal EF

March 27, 2006 - A "third generation" (new) beta-blocker called Nebivolol is on the way. Nebivolol has the main good benefit of Toprol-XL (beta-1 blocking without beta-2 blocking) plus one of the good benefits of Coreg (relaxing the arteries, called vasodilation). It also helps endothelial function and is a powerful anti-oxidant. Nebivolol does this without all of Coreg's side effects.
     Researchers studied how nebivolol affects systolic versus diastolic left heart function in patients. This substudy included 104 patients; 43 had an EF less than 36%. Echo was done on each patient to take quite a few heart measures at study start and again one year later.
     In the group with EF less than 36%, nebivolol reduced heart size and improved EF 5%. Other measures remained the same. In patients with EF higher than 36%, no changes in the heart muscle were seen.
     So in patients with weakly pumping hearts (low EF), nebivolol reduces heart size and improves EF. In patients with near-normal or normal EF (diastolic heart failure) no changes in the heart muscle were seen. None the less, risk of death or heart-related hospitalization improved in both groups in SENIORS.
     The SENIORS trial showed that nebivolol reduces risk of death and heart-related hospitalizations in senior CHFers regardless of EF. What does this mean? It suggests that CHFers with diastolic heart failure may now have a drug proven to help them.
     Jon's note : The average age in the SENIORS trial was 76 years.
 
Source: Eur Heart J. 2006 Mar;27(5):562-8. Epub 2006 Jan 27.
Title: Effects of nebivolol in elderly heart failure patients with or without systolic left ventricular dysfunction: results of the SENIORS echocardiographic substudy.
Authors: Ghio S , Magrini G , Serio A, Klersy C, Fucilli A, Ronaszeki A, Karpati P, Mordenti G, Capriati A, Poole-Wilson PA, Tavazzi L; SENIORS investigators. PMID: 16443607

Drugs and Exercise Tolerance 

Exercise in a healthy person makes the heart relax more quickly and lowers LV pressure faster. The heart muscle actually stretches and gets larger when full of blood just before pumping it out. This increases EF. In a healthy person, these actions help the body handle exercise.
     In DHF, those actions are very limited. The heart's stiffness prevents it from stretching to increase its size when filled with blood. EF does not rise, and patients get short of breath and very tired. Often, there is quite a rise in blood pressure and heart rate during exercise. The rise in blood pressure makes the heart work harder, which screws up the entire pumping cycle.
     These changes increase diastolic pressures. High diastolic pressures reduce lung function and make breathing harder. Low heart output during exercise causes fatigue in the legs and other muscles.
     Small trials show that calcium channel blockers, beta-blockers, and ARBs improve exercise ability in many DHF patients. However, these drugs do not always improve heart function.

Inotropes 

Use inotropic drugs with caution. Since ejection fraction is often okay in DHF patients, inotropes may give no benefit at all. However, such drugs can cause harm in these patients. Inotropic drugs may help in the short-term for lung congestion but even short-term use may cause ischemia, speed up heart rate, or trigger arrhythmias.

Digoxin (Lanoxin, digitalis) 

Digoxin (Lanoxin) strengthens the heart's pumping power. This increases energy demand, which may only show up during stress like exercise or ischemia, when digoxin can worsen diastolic function. With the exception of patients in chronic atrial fibrillation (to slow ventricular rate), digoxin is not recommended for DHF.

Coronary Artery Disease 

In CAD, treatment should aim to reduce the heart's oxygen demand and increase blood flow to the heart. Drugs like nitrates (nitroglycerine), calcium channel blockers, and beta-blockers have all been shown to help. Clearing blocked arteries with angioplasty or CABG may also help diastolic heart failure patients with CAD.

Drug treatment of diastolic heart failure
Loop diuretics Bumex (bumetanide), Lasix (furosemide), Demadex (torsemide)
Thiazide diuretics Hygroton (chlorthalidone), Hydrodiuril, Esidrix (HCTZ, hydrochlorothiazide), Amiloride, Aldactone (spironolactone)
Long-acting nitrates Isordil, Sorbitrate (Isosorbide Dinitrate), Imdur (Isosorbide mononitrate)
Beta-blockers See this page
Calcium channel blockers Norvasc (amlodipine), Cardizem (diltiazem), Isoptin (verapamil), Procardia (nifedipine)
RAS inhibitors ACE inhibitors (see this page), ARBs (see this page), and aldosterone antagonists
Questions and Answers 
Question
Is the rise in DHF cases caused by doctors better recognizing the condition or has there been an actual increase in the number of cases?
Dr. Zile
I think it is both. We are recognizing it better. Also, the general population is aging so high blood pressure, heart disease, and diabetes are rising just because they are more common in the elderly. Age itself causes changes in the heart that encourage DHF
 
Question
Why the controversy surrounding the diagnosis of DHF?
Dr. Zile
The guidelines that exist or have been proposed come from the European Cardiology Society and the Canadian Heart Society, as well as from a recent editorial by Vasan and Levy published in the journal Circulation. They all require that 3 standards be met to diagnose DHF:
 
1)  signs and symptoms of heart failure
2)  normal EF
3)  problems with diastolic function seen by cath or echo
 
I think these criteria are too tight and that number 3 should be eliminated. Ninety percent of patients who fit the first 2 will indeed turn out to have diastolic heart failure confirmed by cath. The problem arises because measuring diastolic function with noninvasive tests like echo is difficult and confusing.
     Why? Echo usually measures what we call the E and A velocities. However, E-wave velocity drops with age, heart enlargement, and DHF. So in someone with congested lungs and signs of high heart pressures those E-waves can appear normal. While the E-wave should be low in DHF patients, it may appear normal if the doctor is not experienced at treating diastolic heart failure.
 
Question
Is finding diastolic problems on an echo that is done for another reason important, even in a patient with no history or symptoms of CHF?
Dr. Zile
Yes. In systolic heart failure, a wide range of patient types is seen - from those with low EFs but no symptoms, to those with mild or moderate symptoms, to class 4 patients with severe symptoms even at rest. The same range is likely to be seen in diastolic heart failure patients
 
Question
Since most of the blood that fills the LV does so in the early part of the filling phase, why does it help to lengthen that phase in DHF patients by slowing heart rate? Doesn't increasing heart rate increase cardiac output?
Dr. Zile
While speeding up heart rate increases output, it also raises pressure, making symptoms worse. In a healthy person, raising heart rate does not change pressures much because the ventricle is able to relax faster as heart rate speeds up.
     However, in DHF patients, the response to increased heart rate is not normal. When heart rate speeds up, the ventricle cannot relax any faster. This raises pressures. By slowing heart rate, you give the ventricle more time to relax, lowering filling pressures. Also, many DHF patients have ischemia. By slowing the heart rate, you reduce the heart's need for oxygen and that helps balance supply and demand of blood and oxygen
 
Question
Seeing that pretty much the same drugs are used to treat both diastolic are systolic heart failure, how important is it to tell DHF from SHF?
Dr. Zile
There are at least 40 well-done trials to guide treatment for systolic heart failure patients. This is not true for DHF, so its treatment is less certain. Even though we say ACE inhibitors will probably help and ARBs may help, and beta-blockers may help, and so on, it is not proven in large numbers of DHF patients. Also, there are differences in the way you use those drugs and in the doses you use.
     The best example is beta-blockers. Treating heart failure in patients with an EF of 30% requires that beta-blocker dose be raised carefully, starting with tiny doses and raising it slowly over several months. In the DHF patient, that very slow rise in dose is not usually necessary.
     Another example is calcium channel blockers. These drugs should not be used in systolic heart failure patients at all, but they may help DHF patients. As another example, diuretic use needs to be much more cautious in the DHF patient since drying them out too much can easily cause too-low blood pressure.
     So even though the same drugs may be used to treat SHF and DHF, there are important differences. It is important for doctors to be aware of the differences when treating CHF patients
 
Question
Have beta-blockers and calcium channel blockers been shown to reverse measurements of diastolic dysfunction?
Dr. Zile
If you give beta-blockers to DHF patients, their relaxation rate gets worse instead of better. Despite this, patients feel better - so measurements don't always agree with how patients actually do while taking a drug. With calcium channel blockers, DHF patients feel better while taking them and their filling rates usually get better. There is a complex relationship between how any one drug affects a person versus how that drug affects the measurements we take of that person's heart function.
     One study that used a calcium channel blocker and another study using an ARB showed improved exercise times in patients taking these drugs. However, neither study showed improved measurements of heart relaxation or stiffness. I don't think you can rely just on measures of heart function to guide treatment.
 
Question
In making a DHF diagnosis, what must be ruled out besides systolic heart failure?
Dr. Zile
Besides excluding SHF, it is also important to rule out mitral valve stenosis and chronic lung disease, both of which can imitate heart failure with a normal EF
 
Question
What blood pressure drugs are most likely to help heart enlargement in DHF patients?
Dr. Zile
Although it hasn't been clearly proven yet, I think drugs that alter the neurohormonal systems work well. They not only lower pressure, but they also reduce the effects of overactive bodily systems. The problem is that in most trials, heart enlargement only goes down about 10 to 15%. This will probably improve heart function but not totally reverse DHF. If those high blood pressure trials had been longer by 5 or 10 years, we might have seen more improvement proven down the road.
     What evidence do I have to support that? The answer comes from patients with aortic stenosis who had their aortic valves replaced. Three to 5 years after aortic valve replacement, ventricular size and stiffness often returned to normal, improving the heart's stiffness and relaxation 

Title: Diastolic Heart Failure: Diagnosis and Treatment
Authors: Dr. Michael R. Zile, Dr. Janet M. Simsic
Source: Clinical Cornerstone 3(2):13-24, 2000

All information on this site is opinion only. All concepts, explanations, trials, and studies have been re-written in plain English and may contain errors. I am not a doctor. Use the reference information at the end of each article to search MedLine for more complete and accurate information. All original copyrights apply. No information on this page should be used by any person to affect their medical, legal, educational, social, or psychological treatment in any way. I am not a doctor. This web site and all its pages, graphics, and content copyright © 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Jon C.

Talk to Jon Site Index