Dilated cardiomyopathy

Question 1

definition 1

Answer 1

is characterized by ventricular chamber enlargement

with impaired systolic contractile unction;

Question 2

examples o defined conditions associated with DCM include

Answer 2

viral myocarditis, chronic excessive alcohol

Question 3

Examples o Dilated Cardiomyopathies

Answer 3

Idiopathic
Familial (genetic)
Inflammatory
Infectious (especially viral)
Non infectious
Connective tissue diseases
Peripartum cardiomyopathy
Sarcoidosis

Toxic
Chronic alcohol ingestion
Chemotherapeutic agents (e.g., doxorubicin, trastuzumab)

Metabolic
Hypothyroidism
Chronic hypocalcemia or hypophosphatemia
Neuromuscular
Muscular or myotonic dystrophy

Question 4

Pathology

Answer 4

Marked enlargement o all our cardiac
chambers is typical o DCM (Fig. 10-2),
although sometimes the disease is limited
to the le t or right side o the heart. The
thickness o the ventricular walls may be
increased, but chamber dilatation is out o
proportion to any concentric hypertrophy.
Microscopically, there is evidence o myocyte degeneration with irregular hypertrophy and atrophy o myof bers.
Interstitial and perivascular f brosis is o ten extensive

Question 5

clinical manifestations o DCM

Answer 5

are those of congestive heart ailure
The most common symptoms of low forward cardiac output include fatigue, light-headedness, and exertional dyspnea associated with decreased tissue perfusion
Pulmonary congestion results in
dyspnea, orthopnea, and paroxysmal nocturnal dyspnea, whereas chronic systemic venous
congestion causes ascites and peripheral edema. Because these symptoms may develop insidiously, the patient may complain only o recent weight gain (because o interstitial edema)
and shortness o breath on exertion

Question 6

Physical Examination

Answer 6

Signs o decreased cardiac output are o ten present and include :
- cool extremities (owing to peripheral vasoconstriction) and low arterial pressure.
- Pulmonary venous congestion results
in auscultatory rales (crackles),
and basilar chest dullness to percussion may be present because of pleural effusions
Cardiac examination shows an enlarged heart with leftward displacement of the apical impulse. On auscultation, a third heart sound (S3) is common as a
sign of poor systolic unction.
- The murmur of mitral valve regurgitation is o ten present as a result o the significant left ventricular dilatation
- I right ventricular heart failure has developed, signs ofsystemic venous congestion may include jugular vein distention, hepatomegaly, ascites, and peripheral edema.
- Right ventricular enlargement and contractile
dysfunction are often accompanied by the murmur of tricuspid valve regurgitation

Question 7

Echocardiography in DCM

Answer 7

enlargement o the a ected ventricle(s)
with little concentric hypertrophy, and global reduction o systolic ventricular unction. Mitral
and/ or tricuspid regurgitation is requently detected due to ventricular dilatation

Question 8

Medical Treatment of Heart Failure Symptoms

Answer 8

Approaches or the relief of vascular congestion and improvement in orward cardiac output
are the same as standard therapies or heart failure . Initial therapy typically
includes salt restriction and diuretics if volume overload is present, vasodilator therapy with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker (ARB),
and a β-blocker in hemodynamically stable patients. For patients with persistent symptoms, the addition o an aldosterone antagonist should be considered. These measures have been shown to improve symptoms and reduce mortality in patients with DCM

Question 9

the safest antiarrhythmic or treating

atrial fibrillation and other supraventricular arrhythmias in patients with DCM

Answer 9

Amiodarone

Question 10

an ICD is recommended or patients with

Answer 10

chronic symptomatic DCM and at least
moderately reduced systolic unction (e.g., LV ejection raction ≤ 35% ), regardless o whether
ventricular arrhythmias have been detected

Question 11

In DCM with heart failure _______
should be considered or patients with a history o venous or systemic thromboembolism, atrial
f brillation, or those with le t ventricular thrombi identif ed by cardiac imaging, especially those
that are mobile or protrude into the LV cavity (and are there ore more likely to embolize).

Answer 11

systemic anticoagulation