UMEM Educational Pearls - By Semhar Tewelde

 

  • Many infants w/cyanotic heart disease only survive w/early surgical intervention
  • The most rapid & effective first-line therapy for stabilization of the crashing neonate is IV prostaglandin E1 (PGE1)
  • PGE1 serves to reopen the ductus arteriosus allowing partially desaturated systemic arterial blood to enter the pulmonary artery and be oxygenated
  • The widespread use of this agent has profoundly decreased morbidity & mortality 
  • The initial dose of PGE1 is 0.1 mg/kg/min
  • ADR for PGE1 include: apnea, hypotension, edema, and low grade fever

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·       Cyanosis in the newborn is defined as an arterial saturation <90% and a PO2 <60 torr

·       To help differentiate between cardiogenic and non-cardiogenic causes initially obtain an arterial saturation on room air and obtain a subsequent measurements on 100% oxygen

·       Infants w/neurogenic or pulmonary causes of cyanosis will demonstrate increases in arterial blood saturation on 100% oxygen while infants with congenital heart disease show minimal elevation

·       There are 3 general sources of arterial desaturation in neonates with structural heart disease:

1.) Lesions with decreased pulmonary blood flow (tetralogy of Fallot, severe pulmonary stenosis/atresia, and tricuspid atresia)

2) Admixture lesions, in which desaturated systemic venous blood mixes with intracardiac blood, and then enters the aorta (transposition of great vessels, partial anomalous pulmonary venous drainage)

3) Lesions with increased pulmonary blood flow and pulmonary edema, in which diffusion barriers and intrapulmonary shunting prevent proper oxygenation (truncus arteriosus)

 

 

 

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  • Ventricular assist devices (VAD) have become an option as bridge to transplant or destination therapy in many patients (prevalence heart failure in US 5.7 million)
  • VADs have significantly improved quality of life by NYHA class & 6 min walk distance 
  • 2 main types of VAD exist, pulsatile (PF) and continuous flow (CF), with 98% being CF
  • Both bleeding and thrombosis are frequently encountered complications
  • Although required systemic anticoagulation increases the risk of bleeding, there is a inherent association between CF VADs and GI AVMs
  • Hypotension a common complication, which should be assessed by ruling out: bleeding, thrombosis, mechanical obstruction, sepsis, and RV failure

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Category: Cardiology

Title: Blunt Cardiac Injury (BCI)

Posted: 1/6/2013 by Semhar Tewelde, MD (Updated: 7/17/2024)
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  • BCI results in a spectrum of outcomes from asymptomatic to sudden cardiac death
  • Normal screening ECG is associated with a 98% negative predictive value 
  • Sinus tachycardia is the most common ECG abnormality among trauma victims
  • Myocardial contusion (MC) is the most common & ambiguous diagnosis following BCI
  • MC has no consensus definition or uniform diagnostic criteria and can be loosely defined as BCI w/mild increase in cardiac biomarkers or frank cardiac dysfunction (e.g. wall motion abnormalities, arrhythmias, conduction disturbances, or SCD)
  • BCI w/ a normal ECG & stable hemodynamics have a benign clinical course and rarely require further diagnostic testing or long periods of close observation
  • Individuals w/ECG abnormalities, hemodynamic instability, or rapid deceleration injury concerning for blunt aortic injury (BAI) warrant imaging of heart and great vessels by echocardiogram and CT scan 

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  • Type 1: Ischemic myocardial necrosis secondary to plaque rupture (ACS)
  • Type 2: Ischemic myocardial necrosis not secondary to ACS, but rather supply/demand mismatch, vasospasm, emboli, anemia, hypoperfusion, and/or arrhythmia
  • Type 3: Sudden cardiac death
  • Type 4a: PCI related
  • Type 4b: Stent thrombosis
  • Type 5: CABG related 

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  • ST-elevation may represent STEMI or other alternative diagnoses (e.g., aortic dissection)
  • Computed tomographic (CT) scanning may help in identifying these alternative diagnoses
  • ACTIVATE-SF Registry consists of patients w/a Dx of STEMI admitted to the ED 
  • 410 patients w/a suspected diagnosis of STEMI, 45 (11%) underwent CT scanning before primary PCI; 2 (4%) of these CT scans changed clinical management by identifying a stroke
  • Those who underwent CT scanning had far longer door-to-balloon times (median 166 vs 75 minutes, p <0.001) and higher in-hospital mortality (20% vs 7.8%, p=0.006)
  • CT scanning before PCI rarely changed management and was associated w/significant delays in door-to-balloon times

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Category: Cardiology

Title: Pulmonary Arterial Hypertension (PAH)

Keywords: Pulmonary Arterial Hypertension (PAH) (PubMed Search)

Posted: 12/17/2012 by Semhar Tewelde, MD (Updated: 7/17/2024)
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  • PAH can be classified as primary (PPH) or secondary pulmonary hypertension (SPH)
  • Epoprostenol a prostacyclin analog was the first primary drug for patients w/PAH
  • Recent clinical trials describe combination therapy as superior in efficacy to traditional monotherapy
  • Varied etiologies of PAH hampers the performance of RCTs for each combination therapy
  • PAH is associated w/diminished endothelium factor & nitric oxide, increased phosphodiesterase enzyme leading to the development of the ET-1 receptor antagonist (ERA) bosentan and the PDE- V inhibitor sildenafil
  • RCTs are currently investigating the efficacy of three news agents in tx of PAH: imatinib, riociguat, and selexipag 

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Category: Cardiology

Title: Coarctation of the aorta

Posted: 12/8/2012 by Semhar Tewelde, MD (Emailed: 12/9/2012)
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  • Coarctation of the aorta (CoA) is the 5th most common congenital heart defect.
  • CoA typically manifests as a discrete constriction of the aortic isthmus.
  • The majority of patients affected present in infancy with varying degrees of heart failure, which reflect predominantly the severity of the aortic narrowing. 
  • Some patients may not present until later in childhood or adolescence,  with upper extremity hypertension,  either due to less severe initial narrowing or to the development of collateral circulation bypassing the coarctation.
  • Tx options include surgery, balloon angioplasty, and stenting.
  • Although early surgery may prevent/delay the onset of hypertension, approximately 30% will be hypertensive by adolescence.
  • HTN is the single most important outcome variable in patients with CoA
  • HTN present in young children is often under-recognized or not treated aggressively enough, screening for cardiovascular & renovascular anomalies is essential  
  • Untreated CoA has significant early mortality, with mean age of death ~30-40

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Category: Cardiology

Title: Kawasaki Disease

Keywords: Kawasaki Disease, Mucocutaneous lymph node syndrome (PubMed Search)

Posted: 12/2/2012 by Semhar Tewelde, MD (Updated: 7/17/2024)
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Kawasaki disease (KD) is the leading cause of acquired heart disease in North American & Japanese children
Children w/KD should undergo a 2-D echocardiogram and electrocardiogram
In the acute phase, the myocardium, pericardium, endocardium, valves, conduction system, and coronary arteries may all be involved
KD shock syndrome is a cardiovascular manifestation that presents with hypotension, LV systolic dysfunction, coronary artery aneurysm, and a shocklike state
AHA recommends KD tx w/a single dose of 2 g/kg of IVIG infused over 12 hours plus high-dose aspirin at a dose of 80 to 100 mg/kg per day in 4 divided doses
More than 50% of coronary artery aneurysms regress within the first 2 years of onset 
Regression is associated with marked thickening of the intima, which  may later stimulate atherosclerosis with a risk for ischemic heart disease

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Category: Cardiology

Title: Rheumatic Heart Disease

Keywords: Rheumatic fever, rheumatic heart disease (PubMed Search)

Posted: 11/25/2012 by Semhar Tewelde, MD (Updated: 7/17/2024)
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Rheumatic heart disease (RHD) causes  ~250,000 premature deaths every year
Worldwide RHD is the leading cause of heart failure in children and young adults
RHD manifests as a combination of fever, polyarthritis, carditis, chorea, erythema marginatum, and subcutaneous nodules (major Jones Criteria)
Mitral valve incompetence is the most common valvular lesion and mitral stenosis usually develops later as a result of persistent or recurrent valvulitis with bicommissural fusion
Eradication of group A streptococcus with penicillin prevents the initial acute rheumatic attack
No treatment for RHD exists other than for its complications, including heart failure, atrial fib, ischemic embolic events, and infective endocarditis

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Category: Cardiology

Title: Long QT Syndrome Part II

Keywords: Torsades de pointes, prolonged QT syndrome (PubMed Search)

Posted: 11/18/2012 by Semhar Tewelde, MD
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When polymorphic ventricular tachycardia (VT) is encountered the 1st step is to examine the QTc interval before/after the VT to see if it's prolonged
Torsades de pointes (TDP) typically begins with a premature ventricular depolarization, followed by a compensatory pause, and then a sinus beat with a markedly prolonged QT interval, subsequently followed by a train of polymorphic VT
The risk of developing TDP correlates with the degree of prolongation of QTc interval
Risk = 1.052x, where X is a 10-ms increase in QTc interval
Tx algorithm: ECG reveals prolonged QTc, review drug hx, discontinue all QT prolonging drugs, suppress early after depolarization (EAD) w/magnesium bolus & infusion, maintain serum K levels >4.5meq/L, consider isoproterenol infusion + cardiac pacing 

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Bazett's Formula QTc = QT/RR1/2 

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Despite advancement of molecular genetics dx of congenital long QT syndrome is based on ECG & clinical characteristics
Typical presentation is that a child/young adult experienced unexplained syncope or sudden death during physical exertion or emotional agitation
Bazett formula (QTc = QT x RR 1/2) is the most widely used method for measuring QTc
A QTc interval longer than 440 ms has been considered prolonged
1st described was QT prolongation w/congenital bilateral neural deafness and SCD (Jervell and Lange-Nielsen syndrome)
The more common form is QT prolongation w/o deafness and SCD (Romano-Ward syndrome)
Beta-blockers remain the mainstay treatment
Implantable cardioverter-defibrillator (ICD) is an effective therapeutic option to reduce mortality

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Category: Cardiology

Title: de Winter T Waves

Keywords: de Winter T wave, proximal LAD occlusion (PubMed Search)

Posted: 11/3/2012 by Semhar Tewelde, MD (Emailed: 11/4/2012) (Updated: 11/4/2012)
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An ECG pattern that signifies occlusion of the proximal left anterior descending coronary artery (LAD) without ST-segment elevation

ST segments show a 1-3mm upsloping depression at the J point in leads V1 to V6 that continue into tall positive symmetrical T waves 
 
QRS complexes are typically not widened or only slightly widened
 
Some patients also display loss of precordial R-wave progression
 
Most patients display 1-2mm ST-elevation in lead aVR

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Category: Cardiology

Title: E-point septal separation (EPSS)

Keywords: E-point septal separation (EPSS), left ventricular function, bedside emergency ultrasound (PubMed Search)

Posted: 10/28/2012 by Semhar Tewelde, MD
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EPSS is an accurate and rapid bedside estimation of left ventricular function

First an image of heart should be obtained in the parasternal long-axis view

The ultrasound cursor should be placed through the anterior leaflet of the mitral valve

Subsequently, M-mode is applied and the distance between the anterior leaflet and the interventricular septum is measured during early diastole

A measurement of 7mm or greater indicates poor EF (see attachment below)

 

 

 

 

 

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Attachments

1210281940_Slide1.jpg (65 Kb)



Category: Cardiology

Title: Cardiac Amyloidosis

Posted: 10/20/2012 by Semhar Tewelde, MD (Emailed: 10/21/2012) (Updated: 10/21/2012)
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Cardiac amyloidosis can present along a spectrum from asymptomatic to severe CHF w/conduction abnormalities

ECG with low voltage + echocardiogram with thickened myocardium should heighten suspicion

Definitive Dx. is myocardial biopsy identifying the infiltrative lesion (MRI w/gad is also supportive)

AL (light chain) amyloidosis is an acquired disease from improperly functioning plasma cells

¨ Rapidly progressive and life threatening

¨ Tx. w/chemotherapeutic agents (+/- BMT)

Transthyretin-related (TTR) amyloidosis is produced by the liver (2 types)

Familial transthyretin-related amyloidosis (ATTR)

Senile systemic amyloidosis (SSA)

¨ Both are slowly progressive

¨ Tx liver transplant (ATTR) and supportive care (SSA)

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Category: Cardiology

Title: Chagas Heart Disease

Keywords: Chagas Disease, AV Block (PubMed Search)

Posted: 10/13/2012 by Semhar Tewelde, MD (Emailed: 10/14/2012) (Updated: 10/14/2012)
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Etiological agent is the parasite Trypanosoma cruzi

Chagas is one of the most common causes of AV block worldwide
 
Most frequent & important manifestation is chronic panmyocarditis resulting in dilated cardiomyopathy
 
RBBB with or w/out left anterior fascicular block is the most common conduction defect
 
Other characteristic ECG abnormalities include atrial and ventricular extrasystoles, intraventricular and/or AV conduction disturbances, and primary ST-T wave changes
 

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Category: Cardiology

Title: Autoantibody-associated Congenital Heart Block

Keywords: Autoantibody-associated Congenital Heart Block, neonatal lupus, CHB (PubMed Search)

Posted: 10/7/2012 by Semhar Tewelde, MD
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Autoantibody-associated congenital heart block (CHB), also know as neonatal lupus, is responsible for the majority (~60-90%) of CHB

This is secondary to maternal antibodies that cross the placenta and may disappear postnatal

Neonatal lupus can result in diffuse myocardial disease both with and without conduction disturbances, structural defects, and electrophysiologic anomalies

Overall mortality is up to 30%, with 15% mortality before 3 months of age

More than 65% of surviving newborns require pacemakers

Maternal screening and fetal echocardiography has allowed routine prenatal diagnosis 

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Category: Cardiology

Title: Heyde s Syndrome

Keywords: Heyde s Syndrome, aortic stenosis, angiodysplasia (PubMed Search)

Posted: 9/30/2012 by Semhar Tewelde, MD (Updated: 7/17/2024)
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Aortic valve (AV) stenosis associated with gastrointestinal angiodysplasia

Proteolysis of Von Willebrand (type 2A) as it passes through the stenotic valve is one culprit of bleeding

Hemostatic abnormalities e.g. GI bleed are often corrected after AV replacement

Valve replacement is only recommended for cardiac symptoms

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Category: Cardiology

Title: Brugada Syndrome

Keywords: Brugada syndrome (PubMed Search)

Posted: 9/23/2012 by Semhar Tewelde, MD
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Autosomal dominant inherited arrhythmic disorder characterized by mutation in sodium-channels
Arrhythmic events are often observed at rest or while asleep, resulting in VF and SCD
Diagnostic criteria consists of 2 parts: (1) ECG abnormalities (2) clinical characteristics
A. ECG abnormalities: incomplete or complete RBBB in right precordial leads (V1-V2) w/
    Type I coved-type ST segment elevation and negative T wave 
    Type II saddle-back ST segment elevation followed by a positive or biphasic T wave 
    Type III ST segment elevation without meeting criteria for type I or II variants
B. Clinical characteristics: hx of VT/ VF, family hx of SCD or abnormal ECG, agonal respirations during sleep, or inducible VT/VF during EP study

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