Hemodynamics Flashcards
Aortic pressure vs peripheral pressure
Ao- decreased amplitude and more prominent incisura. Peripheral- higher pulse amplitude and more prominent dicrotic notch???
Peripheral- widened pulse pressure, steeper anacrotic upstroke, delayed systolic peak, dicrotic notch, slightly lower MAP, loss of incisura
What is bifid pulse
Pericardial constriction- CVP will be raised and the x and y descent is steep and abrupt. different from cardiac tamponade where the y descent is prolonged (?)
Overdampened transducer findings
Loss of dicrotic notch
Pulsus bisferiens
Single pulse with 2 palpable peaks
Steep systolic decline, mid systolic pressure drop, second systolic peak.
Causes: AS+AR, Severe AR, HOCM, IABP, L to R PDA, AV fistulas, hyperdynamic heart
Hemodynamic findings of Aortic regurgitation
High systolic pressure, low diastolic pressure (wide pulse pressure), prominent anacrotic notch. peripheral amplification exaggerated (systolic pressures in femoral artery exceed Ao pressures greatly).
LV Diastolic pressure increases with rapid rising slope.
Ao and LV diastolic pressures may become equal in late diastole
Pulsus bisferiens- two systolic peaks
Peripheral peak systolic pressures _____ central Ao pressures by ____ mmHg due to ________
exceed, 10-20 mmHg, peripheral amplification from reflected waves (steeper upstroke, narrower systolic portion and ?? dicrotic notch - book says less)
Austin Flint murmur
rumbling diastolic murmur best heard at the apex of the heart that is associated with severe aortic regurgitation
Bernheim effect
increased LV volume and LV diastolic pressure are transmitted to the RV and increase RVP
systemic congestion without pulmonary congestion in the presence of diastolic left heart failure. It describes ventricular interdependence in that significant alteration in left ventricular size can affect right ventricular function and result in venous congestion and right heart failure.
Presence of A wave in RV wave form?
Abnormal- decreased RV compliance (pulmonary hypertension, RV hypertrophy or volume overload)
Highly sensitive finding for acute aortic regurgitation on pressure tracing?
Inc LVEDP–> early diastolic opening of AV. atrial systole–> a wave may be reflected onto Ao waveform.
Define Pulsus paradoxus. Give 4 examples.
Inspiratory systolic fall in arterial pressure of 10 mmHg or more during normal breathing
Pericardial disease (cardiac tamponade, constrictive pericarditis), RV infarction, restrictive cardiomyopathy, pulmonary disease
Bainbridge reflex
explained by mechanoreceptors present in the right atrial wall and the cavoatrial junction. When there is an increase in volume, the receptors are stretched and the afferent limb of the vagus nerve is stimulated and travels to the medulla oblongata.1 This results in the efferent vagus nerve removing its tone and increasing sympathetic input. This results in tachycardia and increased inotropy. During inspiration, negative intrathoracic pressure which results in increased venous return and activation/stretch of those mechanoreceptors. This leads to tachycardia during inspiration which in absence of pathologic or iatrogenic causes, is referred to as respiratory sinus arrhythmia.
Pulsus paradoxus mechanism
Under normal physiologic conditions the large pressure gradient between the right and left ventricles prevents the septum from bulging dramatically into the left ventricle during inspiration. However such bulging does occur during cardiac tamponade where pressure equalizes between all of the chambers of the heart. As the right ventricle receives more volume, it pushes the septum into the left ventricle further reducing its volume in turn. This additional loss of volume of the left ventricle that only occurs with equalization of the pressures (as in tamponade) allows for the further reduction in volume, so cardiac output is reduced, leading to a further decline in BP. However, in situations where the left ventricular pressure remains higher than the pericardial sac (most frequently from coexisting disease with an elevated left ventricular diastolic pressure), there is no pulsus paradoxus.
LV transmural pressure- increased which increases afterload and LV wall stress= decreases systolic pressure
Water hammer pulses are? causes?
Large volume pulse with rapid upstroke and rapid downstroke
Causes: AR, PDA, hyperdynamic states (Fever, anemia, thyrotoxicosis, AV fistula)
Conditions that will lead to absence of pulsus paradoxus
AR, ASD, isolated right heart tamponade(?), raised LV diastolic pressure, chest wall immobility
