Digi-Tox? DigiFab! – 8/8/18

Thanks to Michelle for presenting the case of an elderly man with CKD5 presenting with GI symptoms and bradycardia, found to have regularized A fib consistent with dig toxicity!


Clinical Pearls

  • A “regularized” atrial fibrillation rhythm should trigger work up for digoxin toxicity.  This rhythm is generated because of complete heart block.  So the atria continue to fibrillate but no impulse is getting through to the ventricles.  As a result, a junctional (narrow complex) escape rhythm takes over.
  • Elevated digoxin levels can rule in the diagnosis of dig toxicity but normal levels do not rule it out.
  • Risk factors for dig toxicity include: renal dysfunction, hypokalemia, hypomagnesemia, and hypercalcemia.

Clinical manifestations of dig toxicity:

  • Acute: predominantly GI symptoms (nausea/vomiting, anorexia, non-specific abdominal pain)
  • Chronic: predominantly neurologic symptoms (delirium, confusion, weakness, lethargy, disorientation, vision changes)
  • Cardiac manifestations: can be acute or chronic and of greatest concern!

EKG findings:

  • Most common finding ⇒ PVCs!
  • Other arrhythmias: AVB, atrial tachyarrhythmia, ventricular bigeminy, junctional rhythm, bidirectional ventricular tachycardia (RARE and only a few drugs can cause this)
  • Scooped ST depressions (the famous Salvador Dali mustache)
  • Increased U waves
  • QT shortening

Risk factors for developing toxicity:

  • Renal dysfunction
  • Hypokalemia, hypomagnesemia, hypercalcemia

Treatment:

  • Ingestion 1-2 hours ago? ⇒ activated charcoal
  • Indications for using Digoxin-specific antibody fragments (AKA DigiFab)
    • Severe poisoning
      • life threatening/hemodynamically unstable arrhythmia
      • K > 5
      • Organ hypoperfusion (AMS, renal failure)
      • Other considerations before giving DigiFab:
        • Hyperkalemia ⇒ do NOT treat.  DigiFab will lower levels
        • Hypokalemia ⇒ Treat! DigiFab will make it worse
        • Hypomagnesemia ⇒ Treat!
    • Serum digoxin concentration is irrelevant!
  • You’ve ordered DigiFab but pharmacy is taking too long? ⇒ atropine!

Want more? 

Infective endocarditis – 8/6/18

Thanks to Janhavi for presenting the case of a middle-aged man with no significant PMH presenting with acute onset of malaise, myalgias, and a “stubbed toe,” septic with petechiae on palms and soles, found to have mitral valve endocarditis.


Clinical Pearls:

  • Endocarditis is more common in men (2:1)
  • ~50% of cases of endocarditis occur in people with no known underlying valve disease
  • 80% of cases are caused by staph and strep species
  • TEE is the gold standard for diagnosis and recommended when clinical suspicion for endocarditis is high.  TTE is more helpful to rule out disease when clinical suspicion is low.
  • Indications for early surgery based on this NEJM article include:
    • Heart failure
    • Uncontrolled infection
    • Prevention of embolic events

Duke’s criteria:

Major criteria:

  • Blood culture positive:
    • Typical organism in two separate blood cultures
    • Persistently positive blood cultures
    • Single positive culture for Coxiella
  • E/o endocardial involvement
    • Echo positive for vegetation
    • New valve regurgitation

Minor criteria:

  • Predisposition to IE (i.e. IVDU, prosthetic valve, congenital cyanotic heart disease)
  • Fever >38
  • Vascular phenomena ⇒ arterial emboli, pulmonary infarcts, mycotic aneurysms, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesions
  • Immunologic phenomena ⇒ GN, Osler’s nodes, Roth’s spots, RF
  • Microbiologic evidence: positive blood culture not meeting major criteria

Probability of endocarditis:

Definite IE:

  • 2 major, 1 major + 3 minor, 5 minor

Possible IE:

  • 1 major + 1 minor, or 3 minor

Rejected IE:

  • Firmly established alternative diagnosis
  • Resolution of symptoms < 4 days with antibiotics
  • Does not meet definite/possible criteria

Indications for surgery:

  • Valve dysfunction causing heart failure
  • Perivalvular extension with development of abscess, fistula, and/or heart block
  • Fungi or other highly resistant organisms that are difficult to treat with abx alone
  • Persistent bacteremia despite maximal treatment
  • Recurrent embolization with persistent vegetations
  • Large vegetations (>1 cm) with severe valvular regurg
  • S aureus prosthetic valve endocarditis

Indications for early surgery:

  • Heart failure
  • Uncontrolled infection
  • Prevention of embolic events

Complications:

  • Most common cause of death: heart failure
  • Heart block
  • Emboli
    • More likely with s. aureus or S. bovis, veg > 1 cm, or increased veg mobility on echo
    • Antiplatelet therapy initiation is not recommended because of increased risk of hemorrhagic conversion of septic emboli

Want more?

  • Check out this blog post and this great review article in the NEJM.

New A fib, severe MR, and papillary muscle rupture… 7/17/18

Thank you Naina for presenting the case of an elderly man with 20 packyear smoking history presenting with acute onset of dyspnea and scant hemoptysis, found to have new onset A fib and L heart failure secondary to severe mitral regurgitation resulting from papillary muscle rupture!


Clinical Pearls

  • In patients with severe mitral regurgitation (MR) and a normal L atrium size, think about acute causes of MR.  TEE is often indicated to better visualize the valve structure and determine need for operative intervention.
  • MR can be caused by papillary muscle rupture, especially 3-7 days post MI.  Other etiologies of rupture include endocarditis and myxomatous valve degeneration.
  • Patients with rupture present with acute onset hypotension, pulmonary edema, and a hyperactive precordium. A systolic murmur is not always present!
  • Treatment:
    • Aggressive afterload reduction AND
    • Surgery (high mortality rate 20-25%)

Atrial Fribrillation

Categories:

  • Paroxysmal (terminates within 7 days)
  • Persistent (>7 days)
  • Long-standing persistent (>1 year)

Differential for new onset A fib: (PIRATES!)

  • Pulmonary (OSA, PE, COPD, PNA)
  • Ischemia/infarction/CAD*
  • Rheumatic heart disease/mitral regurgitation
  • Alcohol/anemia (high output failure
  • Thyrotoxicosis/toxins (stimulants)
  • Electrolytes/endocarditis
  • Sepsis/sick sinus syndrome
  • Other: HTN*, congenital heart disease, previous cardiac surgery, viral infections

* Most common causes in the US.

Treatment:

  • Rate control (preferred method based on AFFIRM and RACE trials)
    • Beta blockers
    • Calcium channel blockers ⇒ contraindicated in decompensated heart failure
    • Digoxin ⇒ avoid use in renal failure, hypokalemia, hypomagnesemia, or hypercalcemia
    • Amiodarone
  • Rhythm control
    • Methods:
      • Chemical (~30% success rate)
        • Class III (amiodarone, sotalol, ibutilide)
      • Electrical (synchronized to QRS, ~80% success rate)
    • Preferred modality in
      • Hemodynamically unstable
      • Young patient (age <65) or good functional status
      • Early in natural history of disease
      • Failure of rate control agents
      • Heart failure

Capture

Complications post MI:

Picture1

Figure from article by Reed et al. Lancet. 2017.

Papillary muscle rupture:

  • Posteromedial muscle is 6-12x more likely because blood supply is through PDA only. Anterolateral muscle receives dual supply from LAD and LCx.
  • Clinical presentation
    • Acute onset hypotension, pulmonary edema
    • Hyperactive precordium
    • Mid, late, or holosystolic murmur with widespread radiation (though many have no murmur!)
    • Diagnosis requires TTE/TEE
    • Treatment:
      • Aggressive afterload reduction
      • Urgent/emergent surgical intervention (20-25% mortality)

Paradoxical stroke in patient with ASD – 7/9/18

Today, Joe presented the case of a young woman presenting with acute onset of L sided weakness, found to have a paradoxical stroke due to ASD!


Clinical Pearls

  • Paradoxical stroke is a diagnosis of exclusion
  • Atrial septal defects (ASDs) have been associated with cryptogenic stroke (stroke of unknown etiology).  An embolic source is often not identified.
  • Ostium secundum is the most common type of ASD (>70% of cases)
  • Indications for ASD closure include the following
    • Symptomatic patient (DOE, platypnea-orthodeoxia)
    • R sided cardiac chamber enlargement
    • Left to right shunt >1.7:1
    • Before pacemaker or device placement
    • After a stroke
  • What about PFOs and cryptogenic stroke?
    • In the past, the recommendation was not to close them.  However, the 2017 CLOSE and REDUCE trials (as well as the 2013 RESPECT trial) showed that closure of PFO reduces the risk of a second stroke compared with medical therapy alone.  Thus, the latest ACC recommendation is to close PFOs after stroke!

Etiologies of stroke in a young adult:

  1. Hypercoagulable state
    • Inherited disorders
      • Protein C/S deficiency
      • Factor V Leiden
      • Prothrombin 20210 mutation
      • High homocysteine levels
      • Sickle Cell Disease
    • Acquired disorders
      • Pregnancy
      • OCPs
      • Estrogen hormone replacement therapy
      • Malignancy
      • APLS
      • DIC
  2. Vasculopathy
    • Noninflammatory
      • Dissection
      • Trauma
      • Connective Tissue Disease
      • Fibromuscular dysplasia
      • Migraine with aura
    • Inflammatory
      • Vasculitis
        • Large vessel: Takayasu, GCA
        • Small to medium: Kawasaki, PAN
      • Secondary vasculitis
        • Bacterial meningitis
        • HIV
        • Varicella
        • Syphilis
        • TB
        • Fungi (esp cocci)
    • Malformations
      • AVMs –> hemorrhagic
      • Aneurysms –> hemorrhagic
    • Venous
      • Cerebral venous sinus thrombosis
    • Other
      • Moyamoya
  3. Metabolic
    • Vessel injury
      • CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
      • Fabry
      • Homocystinuria
    • Pure metabolic
      • MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes)
      • Organic acid disorders
  4. Drugs
    • Cocaine
    • Meth
  5. Cardiac
    • Congenital
    • Rheumatic valve disease
    • Mitral Valve Prolapse
    • PFO
    • ASD
    • Endocarditis with septic emboli
    • Atrial myxomas
    • Fibroelastoma
    • Arrhythmias
    • Cardiac surgery

Atrial Septal Defects

  • Secundum is seen in 75% of cases
  • Exam findings:
    • Fixed split S2
    • Parasternal impulse
    • Mid-systolic mumur at LSB (can be mid-diastolic also)
    • EKG with RV strain and partial RBBB
  • Indications for closure:
    • After stroke
    • Symptomatic patient
      • DOE
      • Platypnea-orthodeoxia syndrome
    • R sided cardiac chamber enlargement
    • L to R shunt > 1.7:1 (based on TTE findings)
    • Before pacemaker/device placement

 

TB Pericarditis! 6/25/18

Today, we learned about a young man with no significant medical history who presented with fever of unknown origin, noted to have R sided lymphadenopathy and a pericardial friction rub.  Work up revealed a moderate sized pericardial effusion, a thickened pericardium, and a necrotic LN showing caseating granulomas on biopsy consistent with TB pericarditis!


Clinical Pearls:

  • Most common cause of pericarditis in the west is idiopathic.
  • Indications for pericardiocentesis
    • Tamponade
    • Suspicion for purulent/tuberculous/neoplastic pericarditis
    • Moderate to large pericardial effusions not responding to anti-inflammatory therapy
  • Purulent pericarditis occurs in 1% of infectious cases with staph aureus being the most common underlying pathogen.
  • TB pericarditis:
    • Leading cause of pericarditis in high HIV prevalent and resource limited settings around the world
    • Treatment requires anti-TB medications.  Steroids are not routinely recommended but may benefit high risk populations
    • Leading complication is constrictive pericarditis, early therapy does not decrease likelihood of development.

Pericarditis

Diagnosis: (Requires 2 out of the following 4)

  1. Typical chest pain
  2. Pericardial friction rub
  3. EKG with diffuse ST elevations
  4. TTE with an effusion

Etiology:

  • Idiopathic
    • Primary cause of pericarditis in the west
  • Infectious
    • Viral
      • Coxsackie, EBV, adeno, HIV
    • Bacterial
      • Staph aureus (most common cause), TB, strep pneumo, neisseria, legionella, nocardia
    • Other
      • Toxoplasma
      • Echiconoccus
  • Non-infectious:
    • Neoplastic
      • hematologic malignancies, lung CA, breast CA, melanoma, mesothelioma
    • Metabolic disorders
      • Uremia, hypothyroidism
    • Autoimmune diseases
      • SLE, RA, scleroderma, MCD, sjogren’s, vasculitides
    • Cardiac injury
      • Trauma, MI, post-PCI, post cardiothoracic surgery
    • Drugs
      • INH, doxorubicin

Indications for pericardiocentesis:

  • Tamponade
  • Suspicion for purulent/tuberculous/neoplastic process
  • Moderate to large effusions of unknown etiology that are not improving with conservative management

 TB pericarditis 

  • Diagnosis is often delayed or missed leading to constrictive pericarditis and increased mortality
  • Occurs in 1-2% of patients with pulmonary TB.
  • Symptoms:
    • Cough, dyspnea, CP, fever, night sweats, orthopnea, weight loss
  • Exam
    • Fever
    • Tachycardia
    • Elevated JVP
    • Hepatomegaly
    • Ascites
    • Peripheral edema
    • Friction rub
    • Distant heart sounds
    • Kussmaul’s sign (lack of inspiratory decline in JVP), prominent Y descent, pericardial knock
  • Evaluation
    • TTE
    • Sputum AFB and culture
    • PTB noted on CXR 32-72% of the time
    • Pericardiocentesis indicated for diagnosis but does not reduce likelihood of developing complications or death
      • Send fluid studies for cell count, protein concentration, LDH, AFB smear/culture, GS and bacterial culture, ADA, and cytology
      • Fluid has high protein content and lymphocytic/monocytic leukocytosis
  • Complications
    • Constrictive pericarditis (30-60% of patients) even with prompt therapy, more common in HIV uninfected individuals
    • Effusive constrictive pericarditis
    • Myopericarditis
    • Cardiac tamponade
  • Treatment:
    • Anti-TB therapy
    • Steroids?
      • Not routinely recommended and do not consistently prevent complications
      • Could consider in high risk groups with early signs of constriction
    • Pericardiectomy for those with persistent constriction