J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 4, Number 3, June 2012, pages 177-189

Particle Depositions and Related Hemodynamic Parameters in the Multiple Stenosed Right Coronary Artery

Figures

Figure 1. Patient-specific right coronary artery (RCA); (a) axial tomographic image which indicates a multiple coronary stenosis at the right coronary artery; geometry reconstruction (b) pericardial side, (c) epicardial side.

Figure 2. Pulsatile inlet flow, which is the physiologically realistic case, based on flow and pressure waveforms acquired with an intravascular ultrasound Doppler probe in the RCA [26]. (a) velocity input waveform; (b) pressure output waveform.

Figure 3. Computational geometry used for code validation [26].

Figure 4. (a) axial pressure drop and (b) wall shear stress distribution along the stenosis during the cardiac cycle for mean flow rate Q = 50 mL/min.

Figure 5. Pressure drop across the investigated multiply stenosed RCA.

Figure 6. Pressure drop for different time step in the investigated stenosis. Time T2 and T6 correspond to the time steps indicated in Figure 1.

Figure 7. Disturbed flow indicators and computational particle deposition patterns at the peak systole T2 = 0.26 s. (a) cross-sectional transient velocity vector fields; (b) temporal WSS magnitude contours in stenosis ST1 and ST2 (WSS value are in (PA)); (c) particle transport and deposition in the stenosed RCA geometry at the time T2.

Figure 8. Disturbed flow indicators and computational particle deposition patterns at the end of diastole T6 =1 s. (a) cross-sectional transient velocity vector fields; (b) temporal WSS magnitude contours in stenosis ST1 and ST2 (WSS value are in (Pa)); (c) particle transport and deposition in the stenosed RCA geometry at the time T6.

Figure 9. Time evolution of particle transport and deposition in the stenosed RCA at the five critical time levels at the cardiac cycle.

Figure 10. Particle distribution inside to the stenosed RCA during the cardiac cycle. Instantaneous plot of the particle distributions for different time steps in downstream sections of the stenosis ST1, ST2 and ST3. At the end of the cardiac cycle a number of 15 particles (1063 seeded initially at the time T = 0 s) remain inside of the RCA. A number of 7 particles remain in vortical flow patterns result in downstream section of the more sever stenosis ST3.

Tables

**Table 1.** Preoperative Patient Characteristics
Variables	Value
MI = myocardial infarction, PTCA = percutaneous transluminal coronary angioplasty, RCA = right coronary artery
Mean age	44
Gender (M/F)	Male
History of MI	NO
Previous PTCA	NO
Renal insufficiency	NO
Cardiovascular risk factor
Hypertension	Yes
Diabetes	NO
Smoke	Yes
Obesity	Moderate
Angiographic data
RCA stenosis	multiple/severe

**Table 2.** RCA Stenosis Severity
Stenosis	Reference diameter (mm)	Stenosis minimal diameter (mm)	Stenosis length (mm)	Diameter reduction percentage (%)	Area reduction percentage (%)
Stenosis	Reference diameter (mm)	ST1	Stenosis length (mm)	Diameter reduction percentage (%)	Area reduction percentage (%)	3.8	1.76	12	54	77
ST2	3.6	2.6	7	28	53
ST3	3.6	1.68	7	53	80

**Table 3.** Hydrodynamic Parameters According to the Stenotic Flow
Stenosis	Time	Q (l/min)	ΔP (mmHg)	Re_throat	Vmax_throat	WSSmax	WSSmin
ST1	T2	0.351	32.84	1141	2.27	210	10
ST1	T6	0.113	4.62	369	0.734	45	20
ST2	T2	0.37	1.46	865	1.165	110	10
ST2	T6	0.118	0.03	275	0.371	20	10
ST3	T2	0.35	36.78	1118	2.33	250	10
ST3	T6	0.112	4.81	361	0.752	50	10

**Table 4.** Comparison of the Our Results With Experimental and Vivo Data From the Literature
Hemodynamic characteristics	Present study		Experimental Li et al. [29] for 2D model		In vivo data
Hemodynamic characteristics	%DS	Value	%DS	Value	%DS	Value
%DS percent diameter stenosis; * pressure drop from the inlet to the throat; ¹Di Mario et al [27]; ²Siebes et al [28].
Peak velocity (m/s)	28% - ST2	1.165	30%	1.47	-	-
Peak velocity (m/s)	53% - ST1	2.27	70%	3.2	¹69.1 ± 4.8%	2.1 ± 2.8

Reynolds number in the throat (-)	28% - ST2	865	30%	528	-	-
Reynolds number in the throat (-)	53% - ST1	1141	70%	1206	-	-

Peak WSS (Pa)	28% - ST2	110	30%	45	-	-
Peak WSS (Pa)	53% - ST1	210	70%	230	-	-

Pressure drop (mmHg)	28% - ST2	0.03	30%	*8.25	-	-
Pressure drop (mmHg)	53% - ST1	32.84	70%	*39.75	²52.2 ± 8.6%	36.9 ± 17.3