P2.44 Increased Pulse Pressure is Associated with Long Left Ventricular Ejection Duration in Isolated Systolic Hypertensives

Abstract

Background

Apart from stiff arteries, increased pulse pressure is associated with increased left ventricular (LV) contractility. We investigated whether elevated LV performance can be derived from carotid artery diameter waveforms in hypertensives.

Methods

We obtained common carotid artery (CCA) diameter waveforms by ultrasound in 8 isolated systolic hypertension (ISH) patients (sys/dia: 154±17/77±13 mmHg, age 70±8 yrs). By dedicated signal processing we obtained, with good precision (<10%), left ventricular isovolumic contraction (ICT) and ejection durations (ET) from the diameter curve, as well as diastolic diameter (Dd), distension (ΔD), relative distension (ΔD/Dd), and distensibility (DC) and compliance coefficients (CC).

Results

Dd was 7.9±1.0 mm, ΔD was 0.30±0.12 mm, ΔD/Dd thus 4±2%; pulse pressure was 77±16 mmHg. DC was 10±5 MPa⁻¹ and CC was 0.5±0.2 mm²/kPa, clearly linking the elevated pulse pressure to reduced arterial stiffness. Heart rate was 76±18 min⁻¹ while LV ICT and ET were 40±7 ms and 311±46 ms, respectively. LV dP/dtmax, estimated from the diastolic blood pressure-to-ICT ratio, was 1991±566 mmHg/s, suggesting no conspicuous contribution of LV contractility to increased pulse pressure in ISH. Within the group, however, there was a large spread in LV performance primarily related to ET and heart rate. Interestingly, ET showed a strong correlation with pulse pressure (r² = 0.85, p<0.01), suggesting long ejection duration contributes to high pulse pressure in some patients.

Conclusions

Increased left ventricular performance, as reflected by ejection duration, can be observed and discriminated in isolated systolic hypertensives by diameter waveform analysis.