FFR, Sgarbosa, Brugada, Stress testing, Tumors, TAVR, EKG Flashcards
What is the relationship between Angiographic stenosis and Physiologic stenosis?
poor correlation between physiologically significant stenosis and angiographic percent diameter stenosis
Define coronary flow reserve (CFR)?
Ratio measured with a Doppler wire between:
- resting coronary flow velocity and
- hyperemic flow velocity after administration of a vasodilator such as adenosine
*Limited by the fact that it interrogates the entire coronary circulation, both epicardial vessels and microvasculature
In what situation may CFR be abnormal despite a physiologically normal epicardial vessel?
microvascular dysfunction
What variables can affect calculation/reproducibility of resting coronary flow and thus CFR?
- Heart rate
- Blood pressure
Define Fractional Flow Reserve (FFR)?
- maximum myocardial blood flow in the presence of an epicardial stenosis compared with the maximum flow in the hypothetical absence of the stenosis
- FFR = [(Pd-Pv) / Resistance] / [(Pa-Pv) / Resistance] *at Maximal hyperemia
- FFR = Pd/Pa (Pd = distal coronary pressure, Pa = proximal aortic pressure)
What medications are used to induce maximal hyperemia in FFR measurements? Why are these medications used?
- Nitroglycerin –> epicardial artery resistance is minimized and reduces epicardial spasm
- Adenosine –> microvascular resistance is minimized
What characteristic allows for pressure measurements to identify significant lesions in FFR?
Normal epicardial vessels have very little pressure loss along there course (proximal = distal pressure)
What factor allows for elimination of variables (HR, BP, LV contractility) in the calculation of FFR, which normally affect resting hemodynamics?
FFR is measured at maximal hyperemia *eliminates the effects of resting hemodynamics
What is a normal FFR value? What is the ischemic FFR threshold?
Normal = 1.00
Ischemic = < 0.75
Gray zone = 0.75-0.80
What are the unique features of FFR?
- Normal value of 1.0 in every patient and vessel
- Well defined ischemic threshold of < 0.8
- Specific for the epicardial vessel
- Independent of the microvasculature
- Accounts for collateral blood flow
- Independent of hemodynamic changes
- Excellent reproducibility
- Validated against a true noninvasive reference standard
- Extensively validated against clinical outcomes in a variety of patient populations and lesion subsets
Describe the Sgarbossa Criteria
- Concordant ST elevation > 1mm in leads with positive QRS complex –> score 5
- Concordant ST depression > 1mm in any lead from V1-V3 –> score 3
- Excessively discordant ST elevation > 5mm in leads with a negative QRS complex –> score 2
**A minimal score of 3 was required for a specificity of 90 percent.
**the third finding requires further validation, since a high take-off of the ST segment in leads V1 to V3 has been described with uncomplicated LBBB, particularly if there is underlying left ventricular hypertrophy. In a substudy from the ASSENT 2 and 3 trials, the third criteria added little diagnostic or prognostic value
What trial gave rise to the Sgarbossa Criteria?
GUSTO-1 trial -thrombolytic therapy for acute MI
Define the modified Sgarbossa criteria?
≥ 1 lead with ≥ 1mm of concordant ST elevation
≥ 1 lead of V1-V3 with ≥ 1 mm of concordant ST depression
≥ 1 lead anywhere with ≥ 1mm STE and proportionally excessive discordant STE, as defined by ≥ 25% of the depth of the preceding S-wave
In what other clinical situation is Sgarbossa criteria utilized for the diagnosis of MI?
RV pacing (also demonstrates LBBB on EKG)
What is the Brugada criteria used for?
stepwise approach for differentiating VT vs. SVT with aberrancy If any of the four criteria is positive –> VT if non of the criteria are positive –> SVT with abberancy
Define the Brugada Criteria?
- Absence of RS complex in all precordial leads
- R to S interval > 100ms in one precordial lead
- AV dissociation
- Morphology criteria for RBBB or LBBB present in precordial leads
*dominant R wave in V1 –> criteria for RBBB
*dominant S wave in V1 –> criteria for LBBB
*if any are positive –> VT
*all negative –> SVT
Common EKG features of VT:
- Absence of typical RBBB or LBBB morphology
- Extreme axis deviation (“northwest axis”)
- QRS is positive in aVR and negative in I + aVF.
- Very broad complexes (>160ms)
- AV dissociation (P and QRS complexes at different rates)
- Capture beats (occur when the sinoatrial node transiently ‘captures’ the ventricles, in the midst of AV dissociation, to produce a QRS complex of normal duration.)
- Fusion beats (occur when a sinus and ventricular beat coincides to produce a hybrid complex.)
- Positive or negative concordance throughout the chest leads, i.e. leads V1-6 show entirely positive (R) or entirely negative (QS) complexes, with no RS complexes seen.
- Brugada’s sign (The distance from the onset of the QRS complex to the nadir of the S-wave is > 100ms)
- Josephson’s sign (Notching near the nadir of the S-wave -RSR’ complexes with a taller left rabbit ear. This is the most specific finding in favour of VT. This is in contrast to RBBB, where the right rabbit ear is taller.)
What is the expected battery longevity for current ICD generators?
6-10 years, depending on:
- burden of pacing
- pacing threshold and impedance
- need for high-voltage therapies
- vendor or model
Define primary and secondary cardiac tumors? Which are more common?
Primary arise from the heart (0.001-0.03%) in autopsy series.
Secondary tumors have metastasized to the heart *Secondary cardiac tumors are more common
What percentage of primary cardiac tumors are benign?
75% - adults
90% - children
What are the most common primary cardiac tumors in adults and children?
Adults –> myxoma (50% of all primary tumors) Children –> rhabdomyomas and fibromas
What are common symptoms associated with left-sided and right-sided cardiac masses?
Left sided –> stroke, visceral infarction, MI, Peripheral emboli, dyspnea, orthopnea, PND
Right sided –> PE, pleuritic chest pain, dyspnea, peripheral edema, ascites, hepatomegaly
What is the most common valvular tumor?
papillary fibroelastoma
What are features suggestive of malignant cardiac tumors?
Large Broad-based tumors
May completely occupy the cardiac chamber
Pericardial or Hilar involvement.
What are the preferred methods for imaging/diagnosing cardiac tumors (in order)?
TTE
TEE
Cardiac MR
-provides optimal assessment of the location, functional characteristics, soft tissue features of cardiac tumors
T1 and T2 weights sequences can offer further information regarding soft tissue characterization and demonstration of fluid components.
Cardiac CT
Endomyocardial biopsy
Pericardial biopsy or Pericardial fluid analysis
When is enodmyocardial biopsy for cardiac tumor considered:
- diagnosis cannot be established by noninvasive means
- tissue diagnosis can influence course of therapy
- chance of successful biopsy are reasonably high
- procedure performed by experienced operator
What percentage of patients with chest pain and new LBBB have acute coronary occlusion?
2-4%
*no difference in patients who present with old LBBB
What is the sensitivity of ST elevation on EKG (with normal conduction) for cornoary occlusion?
And with LBBB?
- 70%
- 70% (modified Sgarbossa crieteria)
What is the “Rule of Appropriate Discordance?”
When is it used?
- means that in normal LBBB (without MI), ST segment (and usually T-wave) are in the opposite direction (discordant to) the majority of the QRS
- Concordance (ST segment in the same direction as the QRS) is abnormal –> STEMI
- Sgarbossa Criteria
- no evidence of coronary occlusion,
- all ST-T complexes are discordant and appropriately proportional.
- There is no concordant STE.
- 5 mm of discordant STE in lead V2, but the S-wave is 40 mm, for a ratio of 5/40, or 0.125, which is a normal ratio.
**Thus, by the unweighted Sgarbossa criteria, it is anterior STEMI, but by the ratio rule, it is non-ischemic. This turned out to not be MI or acute coronary syndrome, as predicted by the rule.
- subtle concordant STE in lead aVF, almost 1 mm.
- 2 mm of discordant STE in lead III. Since the S-wave is only 3 mm, this is proportionally excessively discordant ST elevation.
**You should be very worried about STEMI here and, if you are reluctant to activate the cath lab, you should at the very least contact your cardiologist for an emergent formal ECHO, and obtain serial ECGs at least every 10-15 minutes to look for evolution.
- tachycardia, which can exaggerate discordant STE, but should never cause concordant STE, which is now clearly seen in leads III and aVF, with reciprocal proportionally excessive ST depression in aVL and aVR.
- Lead V3 has an inexplicable QRS with profound concordant STE.
- So this is clearly diagnostic of STEMI (There is also ST depression out of proportion: > 30% of the R-wave in leads V5 and V6)
- Dx: 100% acute RCA occlusion
What is peak/max VO2?
maximum rate of oxygen consumption as measured during incremental exercise
What is the peak VO2 when patients are generally considered candidates for heart transplantation?
< 14 ml/kg/min
or
< 12 ml/kg/min on beta-blockers
What is normal Cardiac Index (CI)?
Cardiac Output (CO)?
CI = 2.5-4 L/min/m2
CO = 4-8 L/min
EKG findings of LVH:
- increased amplitude (voltage) of QRS
- supported (and strengthened) by presence of secondary ST-T wave changes
- Other: left atrial abnormality, LAD, and/or prolonged intrinsicoid deflection, prominent U waves may be present
EKG Criteria for LVH (Sokolow and Lyone):
Precordial leads
- Sv1 and R v5 or v6 > 35 mm
- R v5 or v6 > 25 mm
Limb leads
-R aVL > 11 mm
EKG Criteria for LVH (Romhilt and Estes Point system)
**5 or more = LVH, 4 or more = probably LVH**
Amplitude (any of the following) = 3 points
- Any limb lead R or S > 20 mm
- Sv1 or Sv2 > 30 mm
- Rv5 or Rv6 > 30 mm
ST-T change = 3 points (1 with digitalis)
Left atrial abnormality = 3 points
Left axis deviation (-30 or more) = 2 points
Intrinsicoid deflection = 1 point
EKG Criteria for LVH (Cornell)
Men: Ravl + Sv3 > 28 mm
Women: Ravl + Sv3 > 20 mm
EKG Criteria for left atrial abnormality
- Prominent notching of P-wave (especially L2) with P-wave duration > 0.12s
- Leftward shift of P-wave axis
- Increased duration and depth of terminal negative portion of P in V1 ( > 0.04 mm-sec)
Key characteristics of RVH
- R/S ratio in V1 > 1 and R wave > 5mm
- QR in V1
- RAD
- Right atrial enlargement
-S1Q3T3 pattern and S1S2S3 pattern
*S1S2S3 pattern due to RVH = (SII > SIII)
EKG criteria for Right atrial enlargement
- peaked P (amplitude > 2.5 mm) in leads II, III, and aVF
- Rightward shift in P-wave axis ( > +75)
- Increased area ( >0.06 mm/sec or amplitude > 1.5 mm) of initial positive portion of P wave in V1
Differential diagnosis of RAD
- RVH
- Lateral wall MI
- Left posterior hemiblock
- COPD
- Normal Young Adult
Differential diagnosis: Prominent R wave or R/S ratio in V1
- RVH
- Ventricular Pre-excitation (WPW)
- Posterior wall MI
- Hypertrophic Cardiomyopathy
- If qR pattern, incomplete RBBB with septal MI
- Normal Variant
What is the equation for the DTS?
What TEE view is this?
How to obtain the view?
What is this view used for?
- ME, Bicaval view
- Obtain ME, A4C –> rotate to 90-100 degrees and turn probe right
- ASD (secundum, sinus venosus), Atrial pathology, Lines/wires, Venous cannula (SVC, IVC)
Describe this view?
What structures should be identified?
- Parasternal Short Axis (PSAX)
- Structures:
- Aortic valve and cusps
- Descending Aorta
- LA (possibly LAA)
- Interatrial septum
- RA
- TV (ATVL, STVL)
- RVOT
- Pulmonic Valve
- MPA (possibly L/R pulmonary arteries)
WPW
- short PR interval ( < 120 ms in adults and < 90 ms in children during NSR)
- slurring of the QRS complex (delta wave), resulting in the QRS complex being > 120 ms and > 90 ms in children (widened QRS complex results from fusion of two electrical impulses, one through the normal AV node and the other through the bypass tract)
- Secondary ST-T wave changes (ST-T segment deviation opposite in direction of main QRS deflection)
