Non-dippers are known to have more severe target organ damage and increased mortality rate. And it is known that essential hypertension deteriorates LA functions. We tried to assess the effects of dipper and non-dipper status of hypertension on LA function in untreated dipper and non-dipper hypertension using tissue Doppler and strain imaging.
Methods
A total 14 untreated dipper hypertension patients (male 71.4%, mean age 45.8±11.5) and 14 untreated non-dipper hypertension patients (male 78.6%, mean age 44.4±10.8) were included our study. The patients whose night time systolic and diastolic BP did not decrease less than 10% were classified as non-dipper hypertensive patients. Atrial strain and strain rate imaging were obtained at selected narrow sample volume. Peak strain rate were measured in late diastole in the basal septal, inferior, lateral and anterior walls of the atrium from the apical 4 and 2-chamber views. Conventional measures of atrial function and Doppler tissue imaging were also evaluated.
Results
LA volume (Dipper:Non-dipper 24.36±3.54: 26.93±3.51 mL/m2, p=0.064) and atrial fraction (Dipper:Non-dipper 39.29±5.60:43.24±6.12 %, p=0.088) were increased in non-dipper hypertension patients, but they were not statistically different. LA active emptying volume (Dipper:Non-dipper 4.53±1.26: 6.19±1.30 mL/m2, p=0.002) and LA active emptying fraction (Dipper:Non-dipper 31.23±7.93: 38.11±6.08 %, p=0.016) were increased in Non-dipper hypertension patients. LA late diastolic peak strain rates were significantly increased in basal septal (Dipper; Non-dipper -1.35±0.32: -1.61±0.20 1/s, p=0.018) and anterior wall. (Dipper; Non-dipper -1.35±0.32: -1.61±0.20 1/s, p=0.047) It also increased in lateral wall but not statistically significant (Dipper; Non-dipper -1.16±0.54: -1.84±0.74 1/s, p=0.062)
Conclusion
The late diastolic peak strain rate was increased in non-dipper hypertension patients. And LA active emptying volume and fraction was also increased in non-dipper state. These findings demonstrated that atrial booster pump function is increased in non-dipper hypertensives.
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