heart failure is a condition in which the cardiac muscle does
not pump blood efficiently through the various valves of the
heart and the remainder of the circulatory system. Either the
right or left ventricle or both and the atria may be involved
in this condition. With failure of the left ventricular myocardium
(heart muscle), the blood tends to backup in the lungs with
elevated pressure causing shortness of breath (dyspnea), orthopnea
(having to sit to breathe) and paroxysmal nocturnal dyspnea,
as well as the accumulation of fluid in the lower extremities
(swelling of ankles and feet and even the abdomen).
Among the many causes severe coronary atherosclerosis (see figures
with ischemic myocardium often scarred by prior myocardial infarctions,
chronic and acute valvular heart diseases (see figures 49,
and various cardiomyopathies (see figures 43a,
The prognosis of patients with heart failure
is generally poor; and in several series 50% of the patients
with severe symptoms died within 12 months. In less severe heart
failure, mortality approaches 50% in 3 to 4 years.
The primary factor determining prognosis is
the left ventricular function, as reflected in the left ventricular
ejection fraction of blood being pumped out with each heat beat.
Other factors that have been shown to have prognostic value
include functional classification; electrolyte abnormalities
such as a low sodium in the blood; elevated levels of plasma
catacholamines etc; poor exercise tolerance; presence of atrial
fibrillation; and coronary artery disease as the etiology of
the heart failure.
Many patients with heart failure, perhaps
30-40%, die suddenly, presumably from ventricular arrhythmias.
Moreover, increasing heart failure is associated with an increased
incidence of ventricular arrhythmias, which may be decreased
by aggressive, successful therapy for heart failure or by the
prevention of a low potassium or magnesium in the blood.
In patients surviving myocardial infarction, the prognosis is
strongly related to the ventricular ejection fraction, in addition
to the amount of heart tissue (myocardium) that becomes ischemic
(lack of adequate oyxgen) during stress and the amount of ventricular
Once patients with heart failure symptoms
have moderate to severe left ventricular systolic dysfunction,
the mortality is quite high, averaging more than 10% per year.
Studies have shown that the administration of an ACE inhibitor
(captopril or enalapril) was associated with a reduction of
morbid events, an apparent slowing of the progression of left
ventricular dysfunction, and a trend toward a reduction in mortality.
Vasodilator therapy of mild heart failure is often appropriate
in an elderly individual. The decrease in mortality with vasodilator
therapy holds for the subgroup of heart failure patients over
the age of 70 years.
The two beta-blockers bisoprolol and metropolol
CR/XL have beneficial effects on total mortality, death due
to progressive heart failure and sudden death when added to
standard therapy with diuretics and angiotensin-converting enzyme(ACE)
inhibitors even in patients with severe heart failure
Reference:Goldstein,S. and others: Metoprolol
CR/XL in Patients with Severe Heart Failure,JACC,Vol.#8,No.4,2001,932-938.
A change from metoprolol to carvedilol and
vice versa preserves the improvement in LVEF in patients with
Reference:Maack,C. and others,Prospective Crossover
Comparison of Carvedilol and Metoprolol in Patients with Chronic