Term
| ECG mean vector analysis: what is "normal?" |
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Definition
Lead I: positive (vector toward left)
AVF: positive (vector downward) |
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Term
ECG mean vector analysis:
RAD |
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Definition
Lead I: negative (vector toward right)
AVF: positive (vector downward)
> 110
pulmonary HTN -> RV hypertrophy |
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Term
ECG mean vector analysis:
LAD |
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Definition
Lead I: positive (vector toward left)
AVF: negative (vector pointing up)
> -30
left ventricular hypertrophy |
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Term
| How can you calculate the resultant mean vector with a biphasic lead? |
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Definition
In a lead with a biphasic wave (--> net zero deflection), the axis will be perpendicular to that lead
Lead I is biphasic - net 0 degrees
--> vector is 90 degrees
Lead III is biphasic
--> vector is 30 degrees |
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Term
| Effects of CHF on volumes and pressures in the heart, contractility, preload, afterload, and venous pressures |
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Definition
Decreased contractility
EDV increases, EDP goes up
Compliance goes down
With hypertrophy, comes new connective tissue -> lower compliance.
“Diastolic dysfunction” – filling problem b/c of decreased compliance
Afterload goes up b/c of larger volumes, and also b/c of increased vascular resistance
SV goes down
All pressures are i/c in severe (bi-ventricular HF) - except MAP (which is N or d/c)
Left HF:
• LV stroke volume = RV stroke volume
• Left sided ejection fraction will be less
• Contractile function is less
• Preload is increased in the left (EDV is increased, ESV is increased, EDP is increased)
• Increased pulmonary capillary pressure -> pulmonary edema
Right HF:
• Assoc with RV hypertrophy
• Elevated PAP and RV pressures
• Peripheral venous pressure increased
• Capillary pressure increases (systemically) -> peripheral EDEMA
• Jugular vein distension (venous pressure is increased)
Bottom line: if you start off with LV failure, you usually end up with biventricular failure |
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Term
| What happens to somatosensory function if you lesion the spinal cord below T6? |
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Definition
| You lose the nucleus cuneatus pathway of the DCML (proprioception, vibration, pressure, discriminative touch) of the upper extremity |
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