ECHOCARDIOGRAPHY SNIPPETS - PART 2

Echocardiography Snippets - Part 2

 

Anatomy of Aorta¹ –

 

Aortic Valve Apparatus consists of -

LVOT, cusps,sinuses and proximal ascending aorta

 

LVOT consists of -

Inferior aspect of anterior mitral leaflet

Interventricular septum

Posterior LV free wall

 

Aortic Root consists of -

Annulus, sinuses and ST junction

 

LV function classification -

 

Normal – EF > 55 %

Mild LV dysfunction – EF 45 – 54 %

Moderate LV dysfunction – EF 30-44 %

Severe LV dysfunction – EF  < 30 %

 

Importance of E’ –   

       

E’ < 8 cm/s – diastolic dysfunction

E/E’ < 8 = normal LA pressure

E/E’ > 15 = LA pressure > 15

 

Tricuspid valve area = 190 / TV PHT (pressure half time)

 

LA Volume –

 

Normal range is 22 ± 6 ml/ m2

Mildly abnormal – 29-33 ml/ m2

Moderately abnormal – 34-39 ml/ m2

Severely abnormal - >= 40 ml/ m2

 

LA volume ≥ 32 ml/m2 is associated with increased incidence of heart failure and is associated with an increased risk of stroke independent of age and other clinical risk factors for cerebrovascular disease.

 

Left atrial volume index [LAVI] ≤ 28 ml/m2  is strongly predictive of normal stress echocardiogram

 

High LA pressure -

A larger pulmonary vein D-wave with rapid deceleration suggests high LA pressure. D-wave deceleration time of <170 ms is indicative of high LA pressure.

 

Formulae to calculate LVEDP and LA Pressure -

 

•       LVEDP= DBP-4V²_{AR end diastolic}

•       LAP = SBP-4V²_MR

 

Volume status and preload responsiveness assessment by -

 

IVC diameter measurement

IVC collapsibility index

LV end diastolic area

LVOT VTI variation with respiration

LVOT VTI variation with passive leg raise

 

 

Characteristics of Vegetation are  –

 

1.    Gray scale and reflectance of myocardium

2.    Present upstream

3.    Chaotic and orbiting

4.    Lobulated/ stringy/ strands with narrow attachment

 

 

Vegetation Risk Score for Complications –

 

Grade 1 – vegetations are fixed, calcified and single

Grade 2 – vegetation has fixed base with free edge, partially calcified and are multiple on single leaflet

Grade 3 – vegetations are pedunculated, denser than myocardium not calcified and present on multiple leaflets

Grade 4 – vegetations are prolapsing, density is same as that of myocardium and extend beyond the valve.

 

Pericardial Effusion –

 

Mild is  < = 5 mm present posterior to heart

Moderate is  5-19 mm present laterally and apically

Large is >= 20 mm present circumferentially

 

 

 VSD Classification - 

 

VSD     Peak Pressure mmHg   LA or LV dilatation    PAP

Restrictive    > 75                    no                              normal

Mod restrict   25-75                ↑                                  ↑

Non restrict   < 25                 ↑↑                                ↑↑

 

Pressure Half Time [PHT] is influenced by  -

 

1.     LA compliance 

2.     LV compliance

3.     Tachycardia

4.     AR 

5.     ASD  

6.     Restrictive CMP

7.     Severe  LV  Hypertension

8.     Ischemia 

9.     Severe Hypertension

 

Criteria  for  diagnosing  hypovolemia  -

 

1.     End Diastolic Diameter [EDD]  <    25   mm  

2.     LV  End Diastolic Area [EDA]     <  55  cm 2

3.     Systolic obliteration of LV Cavity

 

Reference –

1.Perioperative Transesophageal Echocardiography -Robert M Savage.

 

- by Dr Amarja