From the Guidelines
Systolic dysfunction and diastolic dysfunction are two distinct types of heart failure that require different treatment approaches, with systolic dysfunction often responding to medications that reduce afterload and improve contractility, and diastolic dysfunction management focusing on controlling heart rate, reducing congestion, and treating underlying causes.
Key Differences and Causes
Systolic dysfunction occurs when the heart cannot contract with enough force during systole, resulting in reduced ejection fraction (typically below 40%) and inadequate blood pumping to meet the body's needs. Common causes include coronary artery disease, previous myocardial infarction, cardiomyopathies (particularly dilated cardiomyopathy), myocarditis, and long-standing hypertension 1. In contrast, diastolic dysfunction happens when the heart ventricles cannot relax properly during diastole, leading to impaired filling despite a preserved ejection fraction (typically above 50%) 1. This occurs due to stiffening of the ventricular walls. Conditions that commonly cause diastolic dysfunction include hypertension, aortic stenosis, hypertrophic cardiomyopathy, restrictive cardiomyopathy, aging, diabetes, and obesity.
Treatment Approaches
While there are no established guidelines for the treatment of diastolic heart failure, treatment strategies include treating hypertension and preventing or aiming for regression of hypertrophy, accomplished mainly by using angiotensin-converting enzyme inhibitors and angiotensin receptor blockers 1. Strict volume control is necessary, obtained through diuretics and sodium restriction. Prevention of tachyarrhythmia and controlling the heart rate to optimize diastolic filling time are most often achieved using beta-blockers and calcium channel blockers. Furthermore, improving lusitropy and preventing ischemia are also imperative when considering treatment strategy.
Key Considerations
Both types of dysfunction can lead to similar symptoms of heart failure, including shortness of breath, fatigue, and fluid retention. The management of patients with diastolic dysfunction is frequently determined by a set of therapeutic principles, including control of blood pressure, control of tachycardia, reduction in central blood volume, and alleviation of myocardial ischemia 1. In the absence of controlled clinical trials, the diagnosis of diastolic HF is generally based on the finding of typical symptoms and signs of HF in a patient who is shown to have a normal left ventricular ejection fraction and no valvular abnormalities on echocardiography 1.
Recent Guidelines and Recommendations
Recent studies suggest that treatment with candesartan reduces hospitalization related to diastolic heart failure, though mortality benefit was not seen 1. The most effective treatment approach for diastolic dysfunction is to control heart rate, reduce congestion, and treat underlying causes, with a focus on strict volume control, prevention of tachyarrhythmia, and improvement of lusitropy.
From the FDA Drug Label
Lisinopril tablets USP are indicated to reduce signs and symptoms of systolic heart failure [see Clinical Studies (14.2)]. Lisinopril tablets USP are indicated for the treatment of hypertension in adult patients and pediatric patients 6 years of age and older to lower blood pressure. The difference between systolic dysfunction and diastolic dysfunction is not explicitly stated in the provided drug labels. However, systolic heart failure is mentioned as an indication for lisinopril, implying that it is a condition where the heart is unable to contract effectively, leading to reduced cardiac output. Diastolic dysfunction can be inferred to be related to the relaxation phase of the heart, but this is not directly stated in the labels. Conditions that can lead to these types of heart dysfunction include:
- Hypertension: can lead to both systolic and diastolic dysfunction
- Heart failure: can be a result of systolic dysfunction
- Acute myocardial infarction: can lead to systolic heart failure 2, 2
From the Research
Difference between Systolic and Diastolic Dysfunction
- Systolic dysfunction occurs when the heart is unable to contract properly, leading to a decrease in left ventricular contractility 3.
- Diastolic dysfunction, on the other hand, occurs when the heart is unable to relax and fill properly, leading to an increase in left ventricular stiffness 4, 5, 6.
- Diastolic heart failure can occur even when left ventricular systolic function is preserved, with an ejection fraction greater than 45 percent 4.
Conditions that can Lead to Systolic and Diastolic Dysfunction
- Systolic dysfunction can be caused by structural heart disease that leads to decreased left ventricular contractility 3.
- Diastolic dysfunction can be caused by left ventricular hypertrophy and ischemic heart disease 5, as well as hypertension 7.
- Other conditions that can lead to diastolic dysfunction include systemic hypertension and ischemic heart disease 6.
- Both systolic and diastolic dysfunction can result in significant morbidity and mortality, with diastolic heart failure correlating better with prognosis for symptoms and survival than traditional indices of systolic function 6.
Clinical Presentation and Treatment
- Patients with diastolic dysfunction and patients with systolic dysfunction can have nearly identical clinical presentations 5.
- Treatment for diastolic dysfunction may include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, and beta blockers 4, 5.
- Treatment for systolic dysfunction may include dietary advice, medical treatment, and the use of sophisticated devices 3.
- It is essential to distinguish between diastolic and systolic heart failure, as the optimal therapy for one may aggravate the other 4.