UMEM Educational Pearls - Cardiology

• Sports are associated w/an increased risk for sudden cardiac death (SCD) in athletes who are affected by cardiovascular conditions predisposing to ventricular arrhythmias (VA)
• SCD has substantially decreased in Veneto Italy due to the introduction of a preparticipation screening program that identifies unrecognized cardiovascular conditions
• This study included 145 athletes evaluated for VA using a screening protocol of ECG, exercise testing, echocardiography, holter monitoring, and cardiac MRI
• ECG was normal in most athletes (>85%)
• VA were detected prevalently during exercise testing 
• Cardiac MRI detected right ventricular regional kinetic abnormalities (ARVD) in 9 of 30 athletes 
• A total of 30% of these athletes had potentially dangerous VA
• In asymptomatic athletes w/prevalently normal ECG, most VA's can be identified by adding an exercise test 

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• Symptomatic aortic stenosis if left untreated has a high mortality rate (5 yr mortality rate is 50% w/angina, 3 yr mortality rate is 50% w/syncope, and 2 yr mortaltiy rate is 50% w/CHF)
• Standard tx includes medical therapy +/- balloon aortic valvuloplasty
• A recent study comparing standard therapy to transcatheter aortic-valve replacement (TAVR) revealed rates of death at 2 yrs were 68% in standard therapy group vs. 43.3% in TAVR group (p<0.001)
• At 2 yrs the rate of rehospitalization was 72.5% in standard therapy group vs. 35% in TAVR group
• The rate of stroke was higher after TAVR vs. standard therapy in the 1st 30 days
• In appropriate patients with severe AS who are not surgical candidates TAVR reduced rates of death, hospitalizations, and symptoms at 2 yr follow-up

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-Common life-threatening cardiovascular effects of cocaine intoxication include tachydysrhythmias, ventricular fibrillation, myocardial ischemia, and infarction.

-Emergency management of acute cocaine intoxication relies mainly on supportive and symptomatic treatment, w/liberal use of gamma-aminobutyric acid receptor agonists such as benzodiazepines.

-Intravenous lipid emulsion (ILE) therapy has been used successfully to treat cardiac toxicity associated with a variety of lipid-soluble drugs, such as local anesthetics, calcium/beta-blockers, tricyclic anti-depressants, and cocaine. 

-The current hypothesis, called the “lipid sink” hypothesis, suggest that ILE infusion creates an expanded lipid phase in the plasma that absorbs the circulating lipophilic toxin and decreases the amount of free unbound toxin available to bind to the myocardium.

-When life-threatening cardiac arrhythmias (e.g. wide-complex tachycardia/prolonged QT) are not amenable to standard therapy (e.g. sodium bicarbonate/magnesium) consider ILE as a potential option to the current algorithm. 

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• Early CPR performed by laypersons can double the chances of survival in out-of-hospital cardiac arrest (OHCA)
• A retrospective cohort that combined 2 RCT compared the survival effects of dispatcher CPR instruction consisting of chest compression alone or chest compression with rescue breathing
• There was a lower risk of death after adjustment for confounders (adjusted hazard ratio 0.91, 95% confidence interval 0.83-0.99, p=0.02)
• Findings strongly support a long-term mortality benefit of dispatcher CPR instruction strategy consisting of chest compression alone rather than chest compression plus rescue breathing

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• 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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• 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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• 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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• 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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Bazett's Formula QTc = QT/RR^1/2 

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An ECG pattern that signifies occlusion of the proximal left anterior descending coronary artery (LAD) without ST-segment elevation

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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)

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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