Infectious Heart Disease

 

Pericarditis:

The pericardium (pericardial complex) consists of an outer fibrous layer and an inner serous layer. The fibrous pericardium is a flask-shaped, tough outer sac with attachments to the diaphragm, sternum, and costal cartilage

  • Acute pericarditis is more common in men than in women.
    • The most common symptom of acute pericarditis is precordial or retrosternal chest pain, usually described as sharp or stabbing.
    • Pain may be of sudden or gradual onset and may radiate to the back (left trapezial ridge), neck, left shoulder, or arm.
    • Movement or inspiration may aggravate the pain.
    • Pain may be most severe when the patient is supine and can be relieved when the patient leans forward while sitting.
    • Common associated signs and symptoms include low-grade intermittent fever, dyspnea, cough, and dysphagia. In tuberculous pericarditis, fever, night sweats, and weight loss were commonly noted (80%).
    • The most common and important physical finding is a pericardial friction rub, which is best heard at the lower left sternal border or apex when the patient is positioned sitting forward or on hands and knees.
    • Causes
    •  viruses include coxsackievirus B, echovirus, adenoviruses, influenza A and B viruses, Enterovirus, mumps virus, Epstein-Barr virus, (HIV), herpes type 1, varicella-zoster virus, measles virus, parainfluenza virus type 2, and respiratory syncytial virus.
    •  
      • Bacterial organisms Streptococcus pneumoniae and other Streptococcus species and Staphylococcus. Isolated gram-negative species include Proteus, Escherichia coli, Pseudomonas, Klebsiella, Salmonella, Shigella, Neisseria meningitidis, and Hemophilus influenzae.
      • Less common organisms include Legionella, Nocardia, Actinobacillus, Rickettsia, and Borrelia burgdorferi (Lyme borreliosis).

Physical:

  • A pericardial friction rub is pathognomonic for acute pericarditis.
    • The rub has a scratching, grating sound similar to leather rubbing against leather.
    • Auscultation with the diaphragm of the stethoscope over the left lower sternal edge allows the best detection of the rub.
    • Serial examinations may be necessary for detection.
  • Tachypnea may be present.
  • Tachycardia may be present.
  • Patients may have fever.

·         Cardiac arrhythmias: Premature atrial and ventricular contractions occasionally are present.

·         Hepatomegaly, ascites

·         As the volume of pericardial fluid increases, the capacity of the atria and ventricles to fill is mechanically compromised, leading to reduced stroke volume and tamponade physiology.

Best Diagnostic test= Cardiac Ultrasound

Treatments:

1st line therapy is NSAIDs such as Indomethacin

2nd Line therapy is steroids to reduce the inflammation

If is due to bacterial causes the appropriate antibiotic is then 1st line therapy

 

 

 

 

 

Subacute bacterial endocarditis

 

  • subacute bacterial endocarditis (SBE) is often due to streptococci of low virulence and mild to moderate illness which progresses slowly over weeks and months
  • Subacute bacterial endocarditis is more common in patients with an underlying congenital heart defect.
  • acute bacterial endocarditis (ABE) is a fulminant illness over days to weeks, and is more likely due to Staphylococcus aureus which has much greater virulence, or disease-producing capacity

 

  • Any new onset murmur with a fever is endocarditis until proven otherwise
  • Most common cause is Strep Viridans and the mitral valve is most commonly infected
  • Most common cause in IV Drug abusers is Staph Aureus and the most common valve infected is the tricuspid
  • S aureus is the most common cause of acute bacterial endocarditis.

 

  • Roth Spots= hemorrhagic petechiae in the retina
  • Janeway Lesions=painless hemorrhagic cutaneous lesions on the palms and soles finger tips
  • Immunologic phenomena: Glomerulonephritis, Osler's nodes (painful subcutaneous lesions in the distal fingers) positive serum rheumatoid factor

 

Best Diagnostic test= Cardiac Ultrasound

 

These patients need prophylaxis before high-risk procedures

    • Dental procedures (extractions, implants, root canals)
    • Respiratory procedures (tonsillectomy and adenoidectomy, surgical operations, bronchoscopy)
    • GI procedures (sclerotherapy, biliary tract surgery, endoscopic retrograde cholangiopancreatography [ERCP])
    • Genitourinary tract (prostatic surgery, cystoscopy, urethral dilation)

Typical regime is 1gm ampicillin 2 hours before then 2gm 1 hour after the procedure

 

Treatment

penicillin G for 4 weeks

penicillin or ceftriaxone combined with gentamicin for 2 weeks

 

 

Myocarditis

 

  • Myocarditis is collection of diseases of infectious, toxic, and autoimmune etiologies characterized by inflammation of the heart. Subsequent myocardial destruction can lead to dilated cardiomyopathy.
  • The male-to-female ratio is 1.5:1.  The average age of patients with myocarditis is 42 years
  • An antecedent viral syndrome is present in more than one half of patients with myocarditis. The appearance of cardiac-specific symptoms occurs primarily in the subacute virus-clearing phase; therefore, patients commonly present 2 weeks after the acute viremia.
  • Fever is present in 20% of patients.
  • Other symptoms include fatigue, myalgias and arthralgias, and malaise.
  • Chest pain
    • Chest discomfort is reported in 35% of patients.
    • The pain is most commonly described as a pleuritic, sharp, stabbing precordial pain..
  • Dyspnea on exertion is common.
  • Orthopnea and shortness of breath at rest may be noted if CHF is present.
  • Palpitations are common..
  • Tachypnea and tachycardia are common. Tachycardia is often out of proportion to fever.
  • More acutely ill patients have signs of circulatory impairment due to left ventricular failure.
  • A widely inflamed heart shows the classic signs of ventricular dysfunction including the following:
    • Jugular venous distention
    • Bibasilar crackles
    • Ascites
    • Peripheral edema
  • Amongst the infectious causes, viral acute myocarditis is by far the most common.
    • Identification of the coxsackie-adenovirus receptor protein explains the prevalence of these viruses as the causative agents in more than one half of cases. The receptor is the common target of the coxsackievirus B of the enterovirus family and serotypes 2 and 5 of the adenovirus family.
    • Other viruses implicated in myocarditis include influenza virus, echovirus, herpes simplex virus, varicella-zoster virus, hepatitis, Epstein-Barr virus, and cytomegalovirus. Hepatitis C, in particular, is becoming a major focus of research
    • Among the most common drugs that cause hypersensitivity reactions are penicillin, ampicillin, hydrochlorothiazide, methyldopa, and sulfonamide drugs. This syndrome is associated with peripheral eosinophilia, fever, and rash in patients who have biopsy findings of an eosinophilic infiltrate of the myocardium.
    • Numerous medications (eg, lithium, doxorubicin, cocaine, numerous catecholamines, acetaminophen) may exert a direct cytotoxic effect on the heart. Zidovudine (AZT) has been associated with myocarditis.
  • Immunologic etiologies of myocarditis encompass a number of clinical syndromes and include the following:
    • Connective tissue disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and dermatomyositis that can often result in a dismal prognosis
    • Idiopathic inflammatory and infiltrative disorders such as Kawasaki disease, sarcoidosis, and giant cell arteritis
  • Rejection of the post transplant heart may present as inflammatory myocarditis

DX: Cardiac Echocardiogram

 

TX:

Diuresis Lasix

ACE inhibitors and Calcium channel blockers