- 學位論文
瑪爾濟斯犬左心室舒張功能之評估
Evaluation of Left Ventricular Diastolic Function in Maltese Dogs
摘要
左心室舒張功能 ( left ventricular diastolic function，LVDF ) 在心臟衰竭之評估上具有其重要之價值，但在獸醫學此方面之研究鮮少。超音波掃描為評估LVDF首選工具，在人類醫學常被用來作為LVDF異常之傳統性指標者有經僧帽瓣血流之早期舒張波之最高速度 ( peak velocity of early diastolic filling transmitral wave，EV )、心房收縮波之最高速度 ( peak velocity of atrial systolic transmitral wave，AV ) 及其比值 ( EAR )、僧帽瓣E波減速時間 ( deceleration time of mitral E wave，EDT )、僧帽瓣環基部組織早期舒張運動速度 ( early diastolic velocity of mitral annular tissue motion，E`V ) 和心房收縮速度 ( atrial systolic velocity of mitral annular tissue motion，A`V )、E/E`比值以及左心室血流傳播速率 ( left ventricular flow propagation velocity，Vp ) 等；近來研究顯示人類左心室容積指數 ( left ventricular volume index，LVVI )、質量指數 ( left ventricular mass index，LVMI ) 及其比值 ( VMR ) 與LVDF有很好的相關性，可用來評估疑似LVDF異常之病人，且異常LVDF的嚴重度會與左心室質量指數及容積指數呈現正相關。因此，本研究擬針對門診之瑪爾濟斯犬，一方面進行一般臨床、血壓、血液與血清生化、心電圖和胸部X光攝影等檢查，另一方面以心臟超音波掃描儀測定各種左心室舒張功能和收縮功能指標，然後將左心室壁和心室中隔厚度及左心室內徑均在參考值內，且上述各種檢查皆正常之犬隻作為對照組 ( control group，n =23 )，而心臟超音波檢查呈現異常 ( 如僧帽瓣逆流、三尖瓣逆流 ) 之犬隻列為心臟疾病組 ( heart disease group，HD group，n =55 )，再依左心室之容積和質量與體表面積之比值，區分為容積與質量指數均未增加組 ( normal volume and mass index group，NVM group，n =21 )、質量指數增加組 ( high mass index group，HM group，n =13 )、容積指數增加組 ( high volume index group，HV group，n =7 ) 及容積與質量指數均增加組 ( high volume and mass index group，HVM group，n =14 ) 等四組，來比較5組間各種傳統性舒張功能測定值有無差異性以及分析LVVI、LVMI及VMR與傳統性LVDF指標間之相關性。另外5組間常用之左心室收縮功能指標項目，包括射出分率 ( ejection fraction，EF )、縮短分率 ( fraction shortening，FS )、平均圓周纖維短縮速度 ( mean velocity of circumferential fiber shortening，mVcf ) 和左心室射出時間 ( LV ejection time，LVET ) 等之差異性亦被比較，結果顯示各種左心室收縮功能測定值在5組間均無顯著性差異 ( P >0.05 )；而在舒張功能參數方面，LVVI和LVMI均與傳統之LVDF異常指標項目，包括EV、EAR、ED、E/E`、E`/A`和E`V等，呈現顯著之相關性 ( P <0.05 )，顯示LVVI和LVMI亦可用來作為評估左心室舒張功能之指標。此外，為瞭解LVVI和LVMI之分級是否可用來評估左心室舒張功能之嚴重度，先將55隻HD組供試犬依LVVI和LVMI大小分為3組，連同上述正常組共4組來比較其傳統LVDF測定值之差異性，結果在4組間之各種LVDF測定值並無規律且明顯之差異性，顯示此一分級方法無法用來分級LVDF之嚴重度。
並列摘要
It is important to evaluate the left ventricular diastolic function ( LVDF ) for the heart failure but the related study is rare in veterinary medicine. Echocardiography is the first choice for the evaluation of LVDF. Many traditional parameters were used to evaluate the LVDF in humane medicine including peak velocity of early diastolic filling transmitral wave ( EV ), peak velocity of atrial systolic transmitral wave ( AV ), E/A ratio ( EAR ), deceleration time of mitral E wave ( EDT ), early diastolic velocity of mitral annular tissue motion ( E`V ), atrial systolic velocity of mitral annular tissue motion ( A`V ), E/E` ratio, left ventricular flow propagation velocity ( Vp ) etc. Recent study in human medicine indicated that LV volume index ( LVVI ), LV mass index ( LVMI ) and the ratio between volume index and mass index ( VMR ) are significantly correlated with LVDF, and had positive correlation between the severity of the LV diastolic dysfunctional and LVVI and LVMI, so the LVVI, LVMI and VMR are considered as predictors to evaluate LVDF patients. Therefore, in this study the Maltese dogs were used for the object, the examinations of physical conditions, blood pressure, hematology and plasma biochemistry, electrocardiogram and chest radiography were conducted. Besides, the varied systolic and diastolic functions of the left ventricle were measured by using Doppler color echocardiogrphy machine. Next, the dogs with normal LV wall thickness, interventricular septal thickness and LV inner diameter compared to the reference were grouped as the control group ( n =23 ), and the dogs with abnormal echocardiography changes ( ex: mitral or tricuspid valve regurgitation ) were grouped as the heart disease group ( HD group, n =55 ). Then, the HD group were subdivided into four groups including normal LV volume and mass index group ( NVM group, n =21 ), high mass index group ( HM group, n =13 ), high volume index group ( HV group, n =7 ) and high volume and mass index group ( HVM group, n =14 ) by LVVI and LVMI. Various traditional left ventricular diastolic functional parameters were compared among the five groups, and the correlations between LVVI/LVMI and traditional LVDF parameters were analyzed. Additionally, the comparison of the common LV systolic functional parameters including ejection fraction ( FS ), fraction shortening ( FS ), mean velocity of circumferential fiber shortening ( mVcf ) and LV ejection time ( LVET ) were also compared among the five groups. The results revealed that there are no significant differences ( P >0.05 ) in varied measurements of left ventricular systolic function among five groups. The LVVI and LVMI are significant correlation (P <0.05 ) with the varied traditional left ventricular diastolic functional parameters including EV, EAR, ED, E/E`, E`/A` and E`V, it showed that LVVI and LVMI are also as the LVDF indicators. On the other hand, in order to evaluate whether the grades of the LVVI or LVMI are available as the severity of LVDF, 55 HD dogs were divided into three grades according the magnitudes of LVVI or LVMI, then the traditional LVDF measurements were compared among four groups ( including the control group mentioned above ). The results revealed that there are no regular and significant differences among four groups, LVVI or LVMI can not be used as a indictor for grading the severity of LVDF.